My first bitcoin buy was in 2016 september and I'm still regretting about that I did not sell my bitcoins at 20000$ still I believe that it will cross it's ath sometimes and that's why I hold my bitcoins.
This has happened with many people who had entered at high value and thinking that it will continue to rise end up either selling in loss or need to hold til that price is achieved. Greed is something which if not control can case heavy losses at time.