In college, there was a guy on our dorm's hockey team who talked like that - "That which doesn't kill you makes you stronger." His other favorite was "Pain is weakness leaving the body." We tried to point out that sometimes that which doesn't kill you leaves you crippled, and sometimes pain isn't just weakness leaving the body, but important things like blood. These were the kind of conversations that occurred when a military veteran met a group of people whose combat experience was limited to D & D.
He was a heck of a hockey player, though.
I personally feel people say that to make themselves feel better about the crap they go through. Crap happens and that's the way of life, but I don't see the need "to learn" from the experience or take something away from the crappiness. Life is a lot about luck, shit happens to everyone it's the amount of it and the frequency that really seals the deal.