what really puzzles me is how you or anybody can think of teaching as a low aspiration, compared to a marine biologist. ok, so ive only done a quick search but apparently marine biologists start on 14 grand whereas teachers start on 20. headteachers can earn up to about 75 grand, whereas a really specialist marine biologist with a Phd can get 50 grand. so its not by pay
Also while teachers are shaping the minds f the future, "Marine biologists often work analysing, classifying and counting bacteria, plankton, algae and less glamorous creatures such as shrimps, worms and fish larvae" so its not by glamour.
so what are you basing your comparisons on? if its by job satisfaction, well you both want to do what you want to do so hopefully will be equally satisfied