For people who teach/rank kids classes

[mweaver123]

4 years is way young. I think 6 is the very earliest age and that is young. Its like herding cats, a room full of little kids. Hope you have another adult or two to help. You'll need them.

That's what the Klingon pain stick is for...he steps out of line in class and BAM! That'll teach him!

On a more serious note, he might not even be interested in training for all I know. I'm gonna let him try it out (maybe wait a bit after 4...maybe 6, like you mentioned), and if it doesn't work out or he's not interested, I won't force it on him. That'd be the quickest way for him to hate it, I'd think.