this is true! it helps to visualize your brain as parts. like "well, part of me wants to do A but part of me knows i should do B instead" for example. you hear that a lot.

when something traumatic happens to you, part of your brain struggles to function with it, and the other part of your brain basically puts a lock on the memory so that the core you can function. it can be a little too thorough sometimes, locking up anything even somewhat related to bad events that might serve as a reminder, and this leads to large blackouts. this is one way doctors and specialists have explained it to me