I could name a whole list, like Bitclub and Gesis Mining Dash, the hyip's, buying bitcoin a year ago, selling all my alts and trading them for Steem just before the "flagging/downvoting" "marketing" shitwave hit this platform, biggest dissapointment: the delisting of Substratum from Binance which I think is a great project, the shrinking of Smart Mesh which I think was also very promising... Stupid things I've done trading all going, mining bitcoin all going in, not selling my bitcoins in early 2018 but see them shrink in value...

But luckily I discovered Bitcoin in July 2015 :-)