Been involved in bitcoin since 2011. Cashed in too soon. When it hit $20 I thought it was too good to be true and sold all of the several hundred I had mined to that point.

After that I didn't pay attention to bitcoin or altcoins for several years. Finally last year started getting interested again and bought some Dash at around $3/coin. Made the same mistake as before - sold when it hit $16.

Investing in several more coins this time and won't make the same mistake again - holding until I get at least enough to pay off my house and all other debts.