You should know how to jungle by the time you're 30

1-30 takes a while and gives plenty of time to learn how to jungle along with all the other roles. Not to mention that you are not suppose to even be in rank if you haven't learned all the roles.

The excuse "I don't know how to jungle" is null and void. You can say that you're bad at it. But by that time you start rank you should know how.

So shut up with that excuse.