Um actually 🤓
I don't have a copy of the 2e PHB handy, but 1e goes up to different levels for different classes.
Clerics, Fighters, and Paladins go up to 11.
Illusionists, Rangers, and Thieves go up to 12.
Druids go up to 14.
Assassins go up to 15.
Monks go up to 17.
Magic-users go up to 18...