The mindset to have? When you focus on the past, that's your ego. I did this in the past, I won that in the past. When I focus on the future, that's my pride. I'm going to dominate, that's your pride talking. I try to focus on the moment, in the present. That's humility, that's being humble. That's a skill I'm trying to master, and it's been working so far so I'm not going to stop.
Be very suspicious of anyone who tells you humility is a virtue -- that's the Catholicism talking. Keep a healthy ego (though not one that outstrips your ability) and be proud of your accomplishments.