Winning Losing Development and More!

We talk a lot about how winning doesn't matter at the young ages
because it's development that's important.  Is that true?
 If so, why? And if not, how come?  Can knowing the
difference and the context help you become a better player?
 Is losing a lot a good thing?  Is winning a lot a good
thing? Learn all the secrets of the (soccer) universe inside!