I just finished watching Eternal Sunshine of the Spotless mind and tried to not get too weepy about it. It made me think of all the bad moments in my life, or rather in anyone's life, and the things we do to try to purge the memories or at least try to pretend that those moments never happened. I've always known in myself that despite the hurts and the pains I go through, I've never wanted to change anything. I'd rather live with it than completely forget. We'd never grow up if we were allowed to stay in the same constant state of bliss. Happiness gives us growth, but so does sadness too.
It's interesting to think about how the human mind works, and how ephemeral every experience we have is. Yet because of the way our brains our wired, it stays with us for as long as those neurons choose to remain functional. Our entire past is recorded on organic matter, the medium being very fragile, the contents being completely intangible. Wire it wrong, and our perceptions could be fooled and reality is altered.
I've always wondered if people see shapes and colours differently. What I might perceive to be the colour red, to someone else's mind could be the colour blue. The only way I'd know is if I sat behind their eyes for a while.