Idiom expressing quickly realizing there's nothing much to learn

In essence, I'm looking for an equivalent of the European "hitting the ceiling". The context of usage will be similar to "I decided to be a cook aid, but I quickly started hitting the ceiling prompting my decision to become a cook".

I tried my "google-fu" but the only references I was able to find were to a definition of "hitting the ceiling" as "being angry".

Solution 1:

Sounds like the cook aide outgrew their job almost immediately, i.e., hit a learning/personal development ceiling. So, I would suggest as an answer the idiom to outgrow one's job, and obvious variants required by the context.

If you Google outgrow a job, you'll get tons of hits -- and advice on how to tell you've outgrown your job and what to do about it.