A great deal. Imagine you're on a hot streak. Kerp hitting all your draws, winning all the coinflips, really feeling like you're playing your A game. Now you take a bad beat. How do you feel now? Took the wind right out of your sails. It's easy to become emotionally invested in the game because of the nature of the risk, reward, and uncertainty. Personally, one of my biggest leaks is chasing losses, or trying to "get back" at the person who sucked out on me (or if we're being honest, I just played poorly against). It's tricky keeping emotions out of it, but learning to distance them from the outcomes, WIN or LOSE means a solid game over time.