Life can be difficult. Things don't always go the way you want them to, and sometimes you have no control over it. That's when it's time for a sanity check of life. Sanity checks help you confirm that it's not your fault that things have gone wrong and they help you build up your confidence again. If you fail to do a sanity check every once in a while you might end up with low self-esteem. It's not the main point of the sanity check though. The main idea is that you want an answer to this question: "Is the rest of the world insane or is it just me?"
Here's some examples of sanity checks:
- Going to the Sainsbury's (upperclass supermarket) instead of the LIDL (shit) to prove to yourself that shopping does not have to be a horrible experience.
- Accepting a fun job with low pay to show yourself that you can have fun at work.
- Accepting a boring job with high pay to show yourself that work doesn't really matter.
- Traveling to an 'easy' country to have a smooth traveling experience (as opposed to, say, a country where you can't read the road signs and nobody speaks English).
- Hooking up with a decent, normal girl to get over the psycho bitch you dated in the past.
- Hooking up with a crazy wild psycho bitch to get over the boring girl you dated in the past.
The concept of Flow is heavily related to this. If you pick a challenge that is too difficult (impossible country to travel to, crazy difficult job, psycho bitch girlfriend) then you will get disappointed and you'll lose your motivation to do even the easier of challenges that you would otherwise enjoy. On the other hand, if the challenge is too easy then you just can't be bothered. You have to be in exactly the right level of difficulty/comfort to achieve flow. At times when you're not, it's important to do a sanity check afterwards to 'reset' your confidence in yourself and in others and your expectations from the world.