I've downsized several times and later regretted giving up some, but not all, stuff. The bikes and parts are among the regrets. It's why this time, when we packed up for this current overseas trip, that we put everything into storage. Not an item was sold or given away.

I know of a guy who kept all his bikes from his racing days in the 50s and 60s, including one he won a state indoor title on. They were kept in mint condition. Not only are they collector's items now, they are great talking points for visitors.