That seems odd to never gotten mentorship. I was at one time a very good coder. I obviously wasn't born that way, but became that after many years of working alongside [often much] better coders and, in one case, quitting a job when I was ~4 years out of school and realized I wasn't going to get any better at that particular job.
Did you never work with better coders? Did they never talk to you or never do a code review? If they did, that's mentorship.
Did you never work with better coders? Did they never talk to you or never do a code review? If they did, that's mentorship.