Many people have an occasional year where they make very high incomes, for exam when selling a house or even fictional paper gains when exercising stock options

Many people have an occasional year where they make very high incomes, for exam when selling a house or even fictional paper gains when exercising stock options as a startup employee. So, given that they aren't making huge salaries but just had a windfall (which may not even be real in the case of startup options), they may not have accountants or be well equipped for this situation. I had those issues a couple years ago with options, where the government says I had a huge income due to capital gains (on paper).