I don't know which is worse

What makes you say that?

Does that include this forum? What do they say that indicates they have assessed your IQ level?

The only social media I use is here. I've sort of got used to not having anyone to share my interests with, I'm always either to clever for some people and not enough for others and often a mixture of both.

I find it helps to not care too much what other people think - these sort of social apps tend to bring out bad behaviours and intolerances in people which will only rain on your parade if you let it.

In terms of what is useful, then underestimating my intelligence would be preferred as people then have to explain more and this makes it clearer if they actually know what they are talking about or will clarify what they mean / want to know which makes the interaction easier.

Mindfulness is my go-to tool for managing this,

On forums and social media.

I'm a bit confused - what situations does this happen in?