We regret about missing Bitcoin, then about XRP then about Ethereum then Doge then Shiba then Pepe (these are some top of my head and from what I've come across in my crypto term).
Point being there are always new opportunities and dwelling on regrets is futile.
Yeah, I missed Bitcoin, as well as all the altcoins you mentioned, plus a whole lots of others, if I were to start numbering them, I can't really arrive at a figure that is certain.
But yeah, you are right, sitting and regretting all the opportunities missed in crypto will only mean one thing, and that is the fact that you will end up missing even more opportunities, it is futile to dwelling on regrets, what is gone is gone, and no amount of regrets will bring it back, it's like some one losing his or her relationship to death, no amount of crying or tears will bring the dead back to live.
Life have to go on, opportunity will always come and go, if you missed one, better get up and position yourself properly to take advantage of the next one coming, regretting and crying over a closed door, will only make you not notice the doors that are open, until they are closed also.