Olympic Soccer - Men's

Congrats to Mexico on the huge upset over Brazil. It was very much appreciated. There's really not much to be said about a quality played game in which the more consistent side got the victory.

However, I'm still unsure about one aspect of the Olympic game; why is it that only 3 players per team are allowed to be above 23 years of age? Maybe I'm oblivious to some rule but this doesn't make any sense since this doesn't really allow every country to properly represent their side (as was seen in the other upset of GBR when they lost to South Korea).
Nonetheless, the final match was by far the most exciting and enthralling to watch. Congrats to our southern neighbors!