I absolutely hate it when people want to engage in small talk without even checking with me first if I am interested. Then I have to be fake nice and pretend to care about whatever crap they say while inside desperately trying to find a way to disengage without being seen as rude. So I simply started saying “Sorry don’t mean to be rude but I have a lot of things to think about right now so please give me a bit of space to do that” or something similar. Unfortunately passive aggressive “nice” people then get offended and think I am rude when they are the ones invading my private space uninvited.