The past is the past.....Right?

Why do I bother myself with always wanting to 'know' what happen before I was in the picture?

To compare? To be aware of what's to come? Old habits die hard right? Why am I obsessing over things that happened that can not be controlled or changed?
I should just spare myself the heartache and frustration of exposing my brain to the past nonsense.

*Sigh*.....When will I learn?