My personality changes often?

so i try and be funny and talkative(its pretty much all i try and be) and sometimes i can be pretty good at doing that and it seems to come natural when i do it but every once and a while i feel like im being really awkward and i dont know what to say and then i end up making a bad joke(after trying to think of one) so i go from people saying im reallly funny and then too saying im pretty awkard. is this like hormones or what? and i dont think im laking any serotonin or chemicals like that.