Okay so if I'm getting this straight:

Decline - Link dies in OoT. Everyone's sad.

Child Era - Link is successful in OoT but heads back to the past to remain being a kid and warn everyone.

Adult Era - Link is successful in OoT but... does what? Nothing?

It's the adult era stuff I'm still confused on now.

Ugh, sorry if I'm sounding more dense than I usually am. Ocarina of Time is a complex enough game with a child and an adult link.