It's not a mistake as that time we all don't know what will happen. It just called regrets but of course it will charge as experience. I entered bitcoin world when the price is $220 and able to buy and sold coins at $300. Still it's not a mistake but rather playing with the price.
If you are making mistakes you can learn from it and you will do next time better and that can be nice for you.
But sometimes even with lot of mistake experience still other people don't learn from this and the cycle just repeats. Gambling, investing in HYIP sites etc are some of the examples. How many mistakes does a people need to experience before learning from it?