Why not do something really hard every now and again just for the hell of it? Just to know ourselves a bit more in our fully protected lives here? What are we made of? Paper? The funny life secret is that it doesn't make one bit of damn difference whether you challenge yourself or not in terms of the life value or meaning or outcome. The only value in challenging yourself is in curiosity. To me being curious is very important, and far more important than accepting things, including the self, as they are. Curiosity is a journey in itself. Be careful of curious people, they will undo all untruths, like cats with balls of string. Current morality, current social mores, current social loves and hatreds etc, current good vs evil etc, these are all balls of string...ready for the curious and clawed.