I discovered bitcoin when it was about $5 per coin and during that time for several reasons I could not buy it. I discovered eth and xmr when they were around $10 per coin and I could not find a good place to buy them. I discovered netko when it was about $0.05 and I could not get the wallet compiled. I probably had around 40 bitcoins and cashed them all out under $800 and I could name more.
You?
My biggest regret is to be too greedy. Sometimes you can win a bit, and you try to wait more time thinking it will raise up more and more, then it crashes and your gains transforms themselves in loss.
Just keep in mind that a gain is a gain, and trying to have more sometimes is not the good thing to do.