[dusted]

We have progressive tax (which is complicated in itself, as you pay different rates on each paycheck, so, the first N amount, you pay 0% (bit it's not called that, ofc), then up to the next N, you pay some other percentage, and of the money after that N up to the next, you pay yet another percentage).

Then we have for some reason, chosen to subsidize banks, by letting people not pay tax on the percentage of money they pay to the bank that constitutes the interest. Then there are a million other factors that might influence it..

On top of that, you're not actually only taxed for the amount of money you earn in a year, you're taxed by the amount of money you thought, last year, that you were going to earn this year.. and there's more, that I am ignorant about, because I just.. accept that it's a black box and either receive or pay the money they ask at the end of the tax year.