bullet is basically reaction time based or how much your brain is adapt to chess. for example if you’re a long time player you know your opening and can predict your opponent’s move and if they go off your opening you can react. personally at low elo bullet is basically just waiting your opponent out.
yeah i’ve played my opening so many times and gone with every possibility so far that it’s pretty much a reflex for me with pretty much everyone of my opponents moves. i just like bullet cuz a lot of the time i don’t have the patience for a long game.