Specifically thinking of stuff that make your life better in the long run but all kinds of answers are welcome!
I’ve recently learnt about lifetraps and it’s made a huge positive impact on how I view myself and my relationships
As far as I understand it’s decided on a case by case basis. It depends on the situation and person. Lies that make the other person seem less trustworthy can also count as insults (example: “Person XY is using cocaine again!”), and gestures can also be considered insults.
Your example could fullfill both elements of offense, insults (§ 185 StGB) and defamation (spreading things about someone which are not true) (§ 187 StGB).