Spent time using fast typing/data-entry skills in temporary jobs for years and trying to break into difficult, competitive career (journalism) where most people had a degree but still made low wages.
Miserable, low wages at my jobs, no certainty, came close to eviction twice.
Eventually was able to figure out student loans to go to uni. With my degree, got a terrible entry-level job in a writing field that worked me to the absolute bone -- I wrote 1.5 million words for them per year, no joke, and they didn't give any holidays whatsoever or sick time, all that was unpaid (I'm in the US, that's all perfectly legal here).
Applied tons of places once I'd worked there for 18 months, filling my cover letter with discussion of what a fast, hard worker I'd become because of my millions-of-words job. Got a better, living wage writing job that let me live in a big city. Parlayed that into a job in a much better industry to write for, and then ended up finding another job that paid much more in that same industry.
The jobs I'm looking at applying to next year, after my mat leave is over, pay anything from $125-200k. It's a little hard for me to believe, as I was once grateful to make $24k and get (terrible) health insurance.
My younger sister has done a similar thing. She worked waitress jobs and then got a very low-wage, unskilled job in a hospital (pushing around wheelchairs, that sort of thing) while she worked her way through uni. She worked her fingers to the bone, two jobs and full-time classes. After a couple of years, she took a couple of courses that let her get a little bit better jobs in the hospital and got enough people to believe in her and give her recommendations that she got into a professional credential program in medicine that is much in-demand, highly-paid, and lets her get a job anywhere she likes.
My parents are a little flabbergasted that both of their children have entered the realm of the $100k+ earner. Both of them were working-class and didn't get much in the way of education. I think they thought that even if we got our degrees, we'd end up in low-paid teaching or social work type positions, not being a high-paid Silicon Valley creative or treating patients at a top medical center!