When you think of Bulma from Dragon Ball Z, the first you likely think of is annoying. In that series above any other, she's one of the more aggravating characters, often serving no purpose beyond whining and crying. It's practically all she did the whole Frieza arc, even if it did make a bit of sense.
She's not quite as bad in Dragon Ball or Super, having plenty of redeeming moments there, but her personality lends itself to mistakes. Mistakes that she's made plenty of across the whole series. Some of them were silly, while others were done with a very good reason. All of them give us something we can learn from though.
10 Sex Appeal Doesn't Work On Everyone
Bulma is built on sex appeal. This is shown throughout Dragon Ball, to surprising levels, in fact. Upon your first watch through of it, you'll be shocked at just how much is shown for quite an old anime (the sheer number of times Goku is naked is crazy). Bulma is the worst about it, however, offering to show her panties to Goku in exchange for the Dragon Ball.
Naturally, this doesn't work because Goku doesn't even know what a girl is in the first place. He's been so secluded that he thinks Bulma is actually missing something downstairs (which she technically is). It goes to show you that no matter how good you may think you look, not everyone is going to bend over backward to please you.
9 Falling For First Guy She Sees
Bulma's lust for a cute boyfriend is known from the very beginning of the show. It's what she's after the Dragon Balls after all. Her first case of love, at first sight, is when Oolong transforms into a dashing looking gentleman, Bulma slinking right out from her hiding place to introduce herself. It shows she's just as bad as the people she tries to woo with her looks.
The worst cases of this though are being gaga over Yamcha and Zarbon upon first glance. Yamcha ended up a good dude so that would can at least be hand waved a little, but Zarbon? The guy who was literally trying to kill them at that very moment? It shows how drawn to pretty boys she was, a mistake everyone can learn from.
8 Flashing Master Roshi
This ties right back to the first thing on the list and is something even those who haven't watched the show know about. The fact she was willing to flash Master Roshi for the Dragon Ball, even with panties on, shows how manipulative and shameless Bulma is as a character. Even though she gets angry afterward, she has very little issues showing off what she has, so long as she gets something she wants after.
Now the fact she gives Roshi a fuller view than she wants is partially Goku's fault. He's the one that took her panties off, but she also should have been able to notice. With what she's wearing, it's hard to believe she didn't already know. Either way, never make the mistake of flashing people you just met like Bulma.
7 Never Trust A Frog
This goes without saying, amphibians and reptiles, in general, should never be trusted. There's a reason the word snake is used in conjunction with a liar as much as it is. Bulma learned that tidbit the hard way, befriending a frog on Namek while being abandoned by Gohan and Krillin. It's an act the pair does quite often, but can you blame them?
Bulma goes out of her way to rig up a machine that will let the frog speak back to her, being tired of a one-way conversation. Little does she know, the frog is actually Captain Ginyu. Mere seconds after the machine is made, Ginyu changes bodies with her, freeing himself from the awful life of a frog.
6 Helping Zaacro And Raiti
Zaacro and Raiti are two aliens who were stranded on a desolate planet, unable to leave because of their ship. They pretend to be Namekians, leading Bulma, Krillin, and Gohan on a false chase for Dragon Balls. All of this is just a large waste of time (for the viewers too) as it's just a diversion for them trying to steal the ship the trio came in on.
When they get found out, the pair are easily dealt with, trio leaving them stranded again. While not a riveting example of it, Zaarco and Raiti show that you can't trust people right away. You need to give it some time, decipher their motives, rather than blindly following them like everyone is a good samaritan.
5 Blaming Others For Everything
This is the main reason that Bulma is merely a tolerated character by many. While she's far better in Super about it, her need to pass the blame off on everyone else is insufferable for parts of Dragon Ball Z. While you can understand her anger for being left behind while Gohan and Krillin looked for Dragon Balls on Namek, you can't excuse how she acts before then. No matter what the two of them do, it's wrong, and they are ruining Bulma's life, etc.
Namek isn't the only example of this as it's just a character trait for her. Except when it comes to Vegeta later in the series, he can never do any wrong, even if that wrong is killing thousands of people.
4 Standing up To Beerus
This moment is both a mistake and a great character moment. It's great because Bulma is standing up for her husband, saving him from a person who she has zero shot of defeating, a fact she knows. It's painting Bulma's hot-headed nature in a far more positive light, something super does a lot of.
It's also a mistake, however, the slap to Beerus earning her one right back. Beerus's slaps pack a little more punch as well, knocking her out effortlessly. She no doubt knew that would happen when she chose to step in, but you should always pick your battles. Stepping up to someone you know you have no chance against is never a good call.
3 Confronting Zamasu
Another great character moment is also one that was a major mistake. To buy Trunks time to learn the Evil Containment Field, Bulma goes off to distract Future Zamasu. This awesome because it shows how brave Bulma is now, especially when it comes to her family. She's come a long way from being scared of almost everything earlier in the series.
Her big mistake was trying to flirt with him as if a man who wanted to wipe out humanity was somehow going to be wooed by her. It was a very confusing decision on her part, playing a bit into her vanity. That said, there isn't much else she could do considering she isn't a fighter as her husband is.
2 Trying To Make The Time Machine Again
Time travel is a murky thing, there's so much that could go wrong due to the butterfly effect. One little change could vastly affect the timeline, thus the history of the world. This isn't something Future Trunks ever cared about, only wanting to stop whatever great evil was effecting his timeline at the time.
Beerus understands this, outlawing time travel in his time period going forward. That doesn't stop Bulma as she tries to reinvent the time machine Future Trunks had. As expected, Bulma can, given her brilliant scientific mind. Unfortunately, Beerus finds out and destroys the machine, warning Bulma one more time. Sometimes you need to be willing to take no as an answer.
1 Helping Baby
Technically Dragon Ball GT isn't canon, nor is this entirely Bulma's fault considering she was under Baby's control at the time, but her being his right hand is a pretty big mistake. She helped run his operations, including the mass migration of humanity to the reborn Planet Vegeta. It showed how dangerous Bulma could be if she ever put her life to a mind of villainy, using brains rather than brawn.
That's what makes it a mistake that we can all learn from, it's the people with the brains that are far more dangerous than the ones that are all strength.