I regret when i'm not holding XEM and XRP when these price still at 70 satoshi/XEM and 500 satoshi/XRP. I could have around 20 btc atm if i did that.
When I was introduced to cryptocurrency in fees years back,I really believe in Crypto system, but my regret was I fail to invest big in BTC, Eth,EOS Elastos etc. When the value of coin are still high, well I do still have big hope for the system because bull run will come.