There’s this phenomenon that happens with gifted children where they become quite lazy. The reason is really interesting. They get praised for being smart that conditions them to value intelligence… And intelligence is how good you are at something without trying or practicing…
It sounds like you are quite smart when it comes to sales, and once you got that validation that you were the smartest in the group, you got what you wanted so you took your foot off of the gas
I’d suggest not looking at your relationship to self-worth, but your relationship to work and effort, as well as real long-term mastery rather than just short-term validation. This might be a delayed gratification issue,
I agree that your time on Khan will help you because it’s about true greatness, which never comes without effort