Oh, yes - one more thought. Deep thought, mind you
I am not sure I would be 100% ... let's say "jealous"... on someone who, at the age of 22, says "I HAVE TO be retired by the age of 50".
Well...that means that the person plans to, or assumes that until 50, he will probably work in a job that he will be happy to drop as soon as this becomes possible.
At the age of 22 and with so much awarness of life - wouldn't it be wiser to focus on finding a career more like a "life calling", that you would have a hard time quitting at the age of 50 simply because you love what you do so much?
That shouldn't be incompatible with financial success...but why retire at 50? Why not find something to do all this lifetime between 22 and 50, that you would hate parting with at the relatively young age of 50?...