Before I became a pastor, I did a lot of different things. I know my experience is not as varied as some (I never waitressed, for example, knew I would be bad at it). But I did learn some things.
During college... Iworked for two temporary agencies, Employers Overload and another, smaller agency. I took a typing test, typed fast but with lots of mistakes (because I was nervous). The smaller agency took a chance on me anyway, assigned me typing jobs (more money). EO assigned me to other kinds of jobs, including 1) serving coffee and cold drinks at the exclusive investor's lounge in a bank, and 2) filling little plastic bags with pieces of jewelry. I re-took the typing test the next summer, did better, and got better jobs.
Someone scolded me once at the Bank because they didn't think I hustled fast enough to get coffee and cold drinks for the ritzy people who had a lot of money in the bank. They were probably right. I am not a good hustler. I felt contrite, beat myself up, vowed to do better.
I had another job, typing invoices all day, at a company that turned out to be owned by the uncle of a classmate of mine. They didn't ask me back after one day, because the boss thought I was "too slow". My classmate informed him that I had gotten the most invoices done of anyone they had hired. But somehow I didn't look fast.
I once had a job over a school break, where I sat in an office and typed on little index cards of different colors, all about meat. Pink was pork, blue was chicken, green was steak. They didn't have a typewriter desk or chair, so I sat at a table on a chair stacked with phone books. At the end of the week, they asked me if I wanted a job. I guess they thought I was fast enough. I was grateful to be able to tell them I was going back to college.
Lessons: sometimes when you are criticized, it really is something you did. We are not all good at everything. Nobody's perfect. We can all do better. Sometimes, it's just perception, or they are crazy. And sometimes, we do a really good job, really rise to the occasion, doing something awful. And, a variety of work experiences gives us a realistic assessment of ourselves, not perfect, but not awful either, both falling short and excelling -- in due season.