Is 13 the youngest you are allowed to be on here?

Because if that is so then that's not right! Similar world is for the people of all ages? Those who are old enough or intelligent enough. Why do people say if you are younger than 13 you are not supposed to be here? Whats the difference ?
There are some of us that are younger that are very intelligent some more so than adults. Don't discriminate against us. We are not causing any trouble. SW is for everyone? Why not make a 10-12
Age. Group also??