Well, at least I'm glad I never bought any of those coins that collapsed at some point. And I hope none of those in my portfolio will collapse someday.
Sooner or later at least one of your coin will collapse since you're invest in a centralized coin where the developer can easily manipulate the market or scam the investors. I know there's will be a coin that still survive maybe for 5-10 years, but it's just temporary, not forever.
At least I didn't get to invest in any of them that's just my joy right now. The little ones that I still have I'm looking for the slightest opportunity to sell them off.
You need to sell your coins when it's already make enough profit, altcoins are only for trading, not investing.