It might be because you have either signed up for one already or they have denied the date of birth you have entered
you have to make a new account so alright i have answer ur question.
You are not old enough
Legally, you must be thirteen to make a YouTube account.
Don't know, still have the same problem. You figure it out and let meh know :)
because your too old
No, YouTube accounts are free to make.
you can't your blocked
You cant change it, if you really want to change it the only way to do it is to delete your account and to do that you have to go to manage account, delete account, give a reason, and boom you have deleted your youtube account.
you set your age to 18+ so you can watch flagged videos =P
Press on anything and do anything you wont are you serious you cant
That 's possible.. You can get on to Facebook with your facebook username. If you have not facebook username, you can make it now. First go to Account beside of Profile and go to account settings. Then you will see Username in it. Then click change and you can make your user name there.
Google officially brought out YouTube, that's why if you make a YouTube account, it automatically creates a G mail account.