US //baɪ ˌwʌnˈsɛlf//
・UK
It's so lonesome to have tea all by oneself.
It's so lonesome to have tea all by oneself.
There's an enlightening and sometimes slightly painful exercise one can do by oneself to learn a bit more about the origins of how one feels and behaves.
Now by this, I'm assuming that the person means alone as in not taking a class, that is studying by oneself at home or whatever, self-study.