I've travelled that journey for the last couple of years and is still not finished to be where I want to be, attention/ethic wise (but I wasn't that low at the beginning, did alright in school). I've read a lot of stories of that thing happening in a short amount of time, but today you at least need an education probably.
My girlfriend worked as a cleaner two years ago when I met her and hadn't finished "high school (?)" (school between age ~15-18?), she took a "designer education" and didn't finish the easiest math courses or language at the time. Now she's re-taken all missing courses and also added the advanced ones that is needed to become engineer, took two years. Now she just started this week at university, studying 5 year master of science civil engineering.
The change has obviously taken her the whole two years (and when she started she just wanted to study something easier like basic economics), but the big change was at the beginning when she decided she wanted to do something more with her life. I guess she always had the work ethic though considering she woke up 5am to clean, but she had to learn the rest.