Ah, if only my brain would let me selectively forget!
Journaling is actually a way to forget as long as one throws out what one writes and never revisit (which I never do). It works like an accelerated Ebbinghaus curve.
That said, I suspect forgetful people are often less emotionally burdened.
Similar to how heavy sleepers tend not to be grumpy people because nothing prevents them from having a good night's sleep.