http://health.harvard.edu/blog/placebo-can-work-even-know-placebo-201607079926First learned about this concept from Firdavs regarding SAT reading. If you pretend like the text is interesting, reading it becomes much more easier, and more info will be retained from the passage. A simple thought like "dang! The effect of caterpillars on mulberry trees in Peru! So interesting!" could significantly increase your score.
Read in reddit that for the most part of your life, you'll feel neutral. Highs and lows will come, but your emotions will be close to neutral in big picture.
We can apply the principle mentioned above in our life too. Artificially prolong the happy moments and articially shorten the sad ones. Even life really sucks right now, forcefully convince yourself that it's the opposite. Try to find reasons why life is good rn (дети в африке голодают а ты не ешь type of shukr doesn't count).
Helps to feel better about life, increases your average emotional state by a tiny bit.