Chess and life
I've come to an interesting conclusion after thinking through why it is so upsetting to lose a game. I first had to realise that the outcome of a game is not in true correlation with a player's intelligence. There are so many things a game depends on, you need routine to be able to see the possible consequences of your moves. Information is often decisive. You don't know everything, but you can learn. You can easily lose a game because of lack of information instead of lack of intelligence.
And here's the interesting realization: this is true in chess as well as in life. Information or the lack thereof can be decisive. You can be as intelligent as Einstein, but you won't be able to cut a piece of timber in half if you don't know the trade. And if you try and muck it up it still doesn't mean you're stupid.
Of course, you can say that it is quite possible to see if you need extra information to do something, and so you don't even start before you get it, but in reality it's often not so. There are things you can't tell beforehand, problems that only arise when it's too late. That's what you need experience for. And/or a good teacher.