Have you ever supported, bought or mined a coin that died later on? Why did you support it? What did you learn from it?
Not yet, but unless you avoid altcoins completely at some point you're going to do it no one is perfect and at some point you're going to make a mistake and support a bad coin, after that happens to you the first thing that you need to do is to reevaluate your strategy and see if you have made the mistake of support some altcoins that eventually will have the same future.