Everything depends on the way you decide to look at things, you could think about the missed opportunities if you want, but it is preferable to think about how compared to the rest of the population of the world you still bought bitcoin and other altcoins way before they did.
So while being an early adopter would have been nice, there is no guarantee you could have earned a lot of money either, as many early adopters sold their coins when bitcoin was still trading for a very low price.
That's just life. You can be a part of every new opportunity. Opportunities will come that you will always miss out on.
In this line of work, we should always try to see the positive side of things. It's hard, we know but that's the only way we can see our wins. I have missed out on a lot of golden opportunities, one of which was not buying Bitcoin earlier on. If I had started a long time ago when Bitcoin was not very expensive, maybe I would have been better than where I am today. At the same time, like you said, what if I bought it and sold it off at a loss then?
So all I can do now is be thankful that I am involved in Bitcoin now and it happened naturally.
Point being there are always new opportunities and dwelling on regrets is futile.
Having regret in life is inevitable to an extent. We will always regret why we did what we did, or why we didn't do something. We will always make wrong decisions in life and sometimes we might miss out on good things or people too. It is how we deal with that mistake that matters.
We shouldn't dwell on the mistake, but learn from it and become better people and make better decisions.