Variance and results oriented thinking

Variance is huge. Especially in small sample sizes. Even my mother could play poker and would have no clue whether a flush is better then two pair and still win for 30bb/100hands over 300 or even 1000 hands. Not too likely but defenetly possible.
Realising that you cant determine your exact winrate until you have a lot of hands is a major part in the evolution as a pokerplayer. I can remember when I was playing 2nl and one day I was making like 11$ in 10 minutes. And the day after was about the same. I was thinking that I could easily make 20$/hour and then calculated my winnings if I would play 5nl or even 10nl based on that.

My confidence would be skyrocketing and then drop inevitable once variance catched up on me. These big confidence swings do hurt your decisionmaking process, the accuracy you can determine your true winrate and are also projected into your reallife.
The latter is especially key to overcome in my opinion. A couple months ago, I would be extremly moody once I was on a downswing and very confident and happy when I was up a vew buy-ins at that day. The way I talked to people and approached my other areas in life were vastly different depending on my winnings at the tables.
Today, my feelings are no longer dependent on my results at the tables which is a big accomplishment in my opinion.

It is impossible to control the outcome of shortterm results in poker. We are just able to shift it a little bit in our favour.
Focussing merely on something that you cant control doesnt make too much sense. I am rather moody when I play bad now. ;)

I am very unhappy about this session as I was loosing about 50$ on very unnecessary mistakes.

Whenever someone is calling a draw against me without him having the odds, I am now always happy that I made the right play. If he now hits his draw, and let it be a two outer, I remind myself:
Fish only play against me because of variance. If there were no variance and the outcome would be exlusively determined by my skill, he wouldnt play against me. 
Or would you play chess against Garry Kasparov for 10k$? Not very likely. But if there is a 10% chance to win 10k$ against someone else, people get attracted no matter how bad the odds are. Otherwise casinos would go broke if all people would only play if the odds are in their favour.

In that sense: You are the casino, offering gamblers to try their luck in a game they cant win over the long run.

Try to find out what illusions you have in your mindset currently and fight them with logic.