Care to share the knowledge you are refering to, and what you would have done with it if time travel were possible?

I sometimes feel/think the same too (I'm touching fifty), that I should have been more bold / less choosy in the past in certain situations (there's one particular girl from university that I still regret to this day for not pursuing, even though the signs and opportunities were there, and then there's my English teacher from high school with the sexiest bob).

Sorry. Got carried away.