Mood; I bought ETH and sold when I thought it couldn't go any higher. I've bought and sold Tesla and Apple a couple of times thinking it couldn't possibly go any higher. Still made my money back and then some though, so I can't complain.
As for your wish, index funds are your friend, low risk as well. I've got some money safely in a savings account (effectively no return on investment), some in 'play' stonks (-2.19% to +70% return on investment per year, 2020 was really good), and some in a managed investment fund that just spreads things around according to a risk profile (don't have a lot of numbers for that one, but +13.29% so far this year).
This is not financial advice, I'm confident we'll have a market crash again within a year or two, and when investing you need to manage risk; index fund (following e.g. the S&P 500) are relatively safe investments, trading stocks is fine if you don't panic sell, but options and going 'all in' on single stocks is dangerous and not recommended. Don't invest money you can't afford to lose. Don't beat yourself up for not getting in on things earlier.