This thread is proof that closed time loops DO EXIST.
Lord almighty, it's the same misunderstanding over and over. Really, someone who is rewatching the movies needs to note down the time travel explanation scenes, also the scene where TAO is talking about the possible futures of her timeline, so we can threadmark it and put an end to this Dormammu style torture.
I know that part of the Ancient One and Bruce scene went like this, and from another post:
Bruce goes to the Sanctum to retrieve the Time Stone. He talks to the Ancient One who explains that she cannot give away the Time Stone, as it would lead to the eventual destruction of her universe in that timeline. She explains that the Infinity Stones create the flow of time and if one is removed, then the flow splits creating a branch reality. Eventually, she gives up the Time Stone after Bruce tells her that Strange said it was the only way.
[one yellow line is displayed]
TAO: Remove one of the stones, and that flow splits.
[shows a black line splitting off the yellow line]
TAO: Now this may benefit your reality. But my new one, not so much. In this new ??? (bartriach?), without our chief weapon against the forces of darkness, our world will be overrun. Millions will suffer. So tell me doctor, can your science prevent all that?
BRUCE: No. But we can erase it. Because once we're done with the stones, we can return each one to its own timeline, at the moment it was taken. So chronologically, in that reality [puts time stone back on yellow line], it never left.
Later on she say "I can't risk my reality on a promise." When Bruce promises not to die, so the stones can be returned to their timelines.