This probably is the case when you only expect money as a direct return on your investment. The proportions probably would be different (I have no idea what would they actually be though) if we considered other things you get in return. E.g. development of your personality, social connections you make etc. You still have to do some work to convert these into money and happiness though.

I even believe educational institutions like colleges and universities are a waste of time if all you want is new knowledge you can apply - most of it already is available online either for free or for much less than what tuition actually costs. A university/college is a tool for social integration (through getting your knowledge formally recognized and through meeting new resourceful people) and the art of using this tool right is another skill most of the people lack and don't even know of.