This is the mindset I like to keep.
When I play I keep in mind that I am capable of beating anyone, be it a random guy or flusha himself. Because in the end we're all playing the same game and years of experience dont give you anything that you can't get on your own. There are no OP classes or perks that give one player an advantage over the other. We're all on an equal playing field. Experience only gives you knowledge about the game (timings, angles, etc.) which will not make you invincible.
Confidence goes a long way in this game.. If you go into an aim-duel thinking you'll win chances are you will. If you are stuck in a 1v2 and dont believe you can do it chances are you wont. It's that simple.
To swing this back around to the original topic:
If every time you get outplayed you call hax, you'll never learn how to prevent getting outplayed again. Sure there are plenty of real hackers out there, but do yourself a favor and figure out how you could win that duel the next time (unless they're blatantly spinbotting/walling), and be confident you will. You can still add fishy players to your vacstatus list, but dismissing anything a better player does as hacks will not help you improve on your own.
/endrant