Different people have different levels of heat resistance. My dad will abort mission, if you shake the pepper shaker more than once. Obviously, he doesn’t have it in him to go back for seconds. I do, but having grown up in that household, it takes a while for the same heat resistance to build up. I bought sriracha for the first time a few months ago, and you could certainly still melt my face off with it, despite me using it again and again.