Happiness advice is hard to compose, since we're all born with different brains, producing different chemicals in different quantities at different levels of efficiency.
"Try regular exercise!" chirrups an influencer whose brain has never known a day of depression in its squiggly grey life.
But I do think I've noticed behaviours that poison joy, and I haven't ever heard it as advice. My theory: bullying is bad for your happiness.
Of the four types of bullying, three of them - intimidation, humiliation and harassment - are usually committed by insecure people, trying to make themselves feel more powerful by taking that power from another.
(The fourth type of bullying is exclusion, and I have no citations for any of this, since it's just a bunch of stuff I reckon. I do think I'm right though, for what it's worth.)
The least happy comedians I've met are the ones who smoke weed in their flats while watching and scoffing at clips of their rivals. Their enemies. Their friends.
I'm slightly transfixed by the story of a relatively well-known comedian who became obsessed with the Instagram stories of an amateur comic. The established comic would watch the videos, share them with friends, play them at parties - mocking the comic's lack of self-awareness.
This newer comedian wasn't internet famous or anything. Just a guy starting out, trying his hand.
To operate like this, you must believe that some people have value, and others do not. Once you've decided this, how can you expect your brain to permanently accept that you're one of the worthy? You can make yourself feel powerful in the short term by humiliating another. But in the long term, you curate a worldview where a person's eccentricities are a reason they deserve to suffer.
Good luck enjoying what you see in the mirror.