Thanos had many great lines across Avengers: Infinity War and Avengers: Endgame. Actor Josh Brolin's voice acting rung out with an imposing and thunderous baritone that made the Mad Titan even more intimidating than his hulking purple form already made him. Thanos easily became the most memorable villain of the MCU films in these two cosmic epics, and his thoughtful & often quite deep lines of dialogue are a central reason for that.
That said, some of Thanos' lines were a little cryptic and may even confuse a viewer on the first viewing. The MCU is a vast universe with deep layers of lore that haven't been fully played out yet on the silver screen. However we're here to help clear that up with 10 Thanos lines, explained.
10 I Ignored My Destiny Once...
The full line is: "I ignored my destiny once. I cannot do that again. Not even for you. I'm sorry, little one."
This is actually referencing what happened to his home planet, Titan. Thanos didn't take the drastic measures he felt necessary to save Titan. Instead, he let things go on the path they were already on, and the planet apparently consumed itself. In fact, it was destroyed to such an extent that the gravity was distorted, as audiences witnessed during the fight between Thanos and the Avengers on Titan.
9 I Know What It's Like To Lose
This line, spoken to Thor and Loki aboard the Asgardian ship. This is also referencing the tragedy that befell Titan. However, it can also be expanded to his trusting the retrieval of the Infinity Stones to beings like Loki and Ronan the Accuser. They were both beaten by the likes of the Avengers and the Guardians of the Galaxy, prompting Thanos to "Do it myself," as he says in the post-credit scene of Avengers: Age of Ultron.
8 You're Not The Only One Cursed With Knowledge
This is said to Iron Man on Titan by Thanos. This is a line that actually puts Tony Stark on Thanos' level, and the Mad Titan shows a measure of sympathy in the statement. Iron Man did something extreme to do what he felt was necessary to protect the world in creating Ultron as well as signing up with the Sokovia Accords.
Thanos is likely aware of at least the former action considering it involved the Mind Stone, and it makes Thanos think that he and Iron Man are kindred spirits– at least to a point. It also shows how committed Thanos is to his solution of wiping out half of all life in the universe.
7 I Hope They Remember You
This further expands on Thanos' respect for Iron Man. Stark fights Thanos to the bitter end, and Thanos would have simply killed Iron Man had Doctor Strange not intervened. However, this commitment and mettle made Thanos respect Iron Man despite the two being adversaries.
6 This Day Extracts A Heavy Toll
Thanos says this on Titan upon meeting the Avengers and Guardians that were waiting for him there, after they reveal that the Ebony Maw is dead. Thanos is primarily referring to Gamora, but he clearly has some sympathy for the death of the Maw. This is actually a vast departure from Thanos of Marvel Comics, who sees the Black Order only as soldiers and doesn't care whether they live or die– so long as they serve him.
5 Everything
The famous and heartbroken "Everything," spoken by Thanos at the end of Infinity War is said to the childlike spirit of Gamora in what seems to be the world within the Soul Stone. Again, this line refers to the heartbreak felt by Thanos not only by the demise of Gamora herself but also by the death of the entire Black Order. He lost all of his closest followers in his quest for the Infinity Stones, and Thanos feels it.
4 I Never Taught You To Lie. That's Why You're So Bad At It.
Thanos is many things, but deceptive and dishonest are not among them. Thanos is upfront with his intent and action. He is a man confident in his own mission and in himself. This line is said to Gamora aboard Sanctuary I, and it comes off as deeply disappointed. Gamora is Thanos' favorite child, and she lied to him to keep the Soul Stone hidden. Dishonesty isn't a quality Thanos wants to see in any of his children.
3 I Will Shred This Universe Down To Its Last Atom
The intent of this line is actually pretty clear, but it's an interesting one because it harkens back to the Thanos of Marvel Comics. The Thanos of the films is a dispassionate nihilist that thinks things can only be improved if the entirety of sentient life has a course-correction.
In the comics, Thanos is a sadist who enjoys nothing more than spilling blood in the name of his beloved Lady Death, and he has attempted to reshape the identity of the very universe to suit his quest several times.
2 I'm A Survivor
This one also references the tragedy of Titan, as Thanos seems to be the only survivor of the planet (as far as we know). He views it as a tragedy without equal, and he is aware of how it has shaped him. Again, Thanos knows who he is, and he is sure of himself. Furthermore, he is aware of his own power, as Infinity War and Endgame show how hard Thanos is to kill.
1 I Am Inevitable
This speaks to Thanos' ego and also harkens back to the Marvel Comics version of the character. He views himself as a universal constant. He is a necessity to correct the universe. In a way, he views himself like entropy– a growing black cloud on the horizon that will only swell in size until the storm comes. In the comics, Thanos made himself an emissary of death and destruction through his own dabblings in inhumane science and the most profane magics. He is akin to a god, and he is inevitable. He will destroy all things one day and will never stop trying to make that day today.