I believe in a deterministic universe. It's a fact that I, and every other player on this planet as well, always tries their very best to win at this game, but sometimes 'luck' doesn't seem to cooperate ...
But luck is just a word. What really happens is that we weren't meant to win this particular pot, or this or that tournament. When we encounter a bad beat we only meet what the universe had in store for us since the moment we were born. For instance, if I had been dealt this same hand five minutes earlier or later I would've won, but we just cannot escape our destined fate.
If you visit a hardware store and find out they don't sell lemonade, do you cry and weep about that? No, that'd be utterly silly because you aren't meant to ever find lemonade there, regardless of how lucky you think you are. And just as silly is it to lament and being sad about how your decisions, smart and deliberate as they were, didn't yield the desired outcome.