'being weird' seems like code for being quiet or disagreeable, not matching another person's ideals, calling them out or making them see something different to what they normally perceive as normal, a realisation of another person's perception that throws a different light on their own.
being weird could also be a physical state of being, be thinking about something weird, it manifests on your face. being weird can consume you. being weird can mean being too quiet, being too loud, being a notable quantity of anything5
on the other side of being, when someone says you're being weird, I feel something pull on the sides of my neck, as if I'm being pulled backwards, then also my stomach feels like I've fallen, but only briefly. and then a desire to prove that no... I am not that weird. maybe attempt to show the rationality behind my weirdness
or perhaps you do not understand your weirdness and cannot perceive why other people see your behaviour as something remarkable or unusual because this seems usual to you, normal.
being weird makes you palpably aware of other people's being, one of those crude awakenings to others' otherness and simultaneously an awareness of not being the centre of 'it all'.
[just a thought:] nobody benefits from when you call someone out on being weird cause it's like neither of you have accepted your unimportance