They may take the basic rate of income tax off the earnings at source and then claim the rest at the end of the fiscal year, in which case you could theoretically get a rebate if your overall earnings fall short of the basic income tax rate once expenses are taken into account, but they don't actually tax the same income twice...
...unless you're American (and a few other countries) where the country you earn the money in gets to take their share and any shortfall between their taxes and America's own taxation levels America will tax you on, I understand. It's why Terry Gilliam eventually renounced his American citizenship as he kept having to pay additional taxes to America despite having not lived there for decades.
I don't know what it's like in other countries but I know a lot of people are very naive about taxation where I live because your tax is typically deducted via your employer's payroll before it gets anywhere near your bank account and thus people don't need to understand it properly. It's really not difficult to set aside money for tax purposes as you earn it and never think of it as "your" money. It is pretty galling, mind, when you receive enough in one go that it'll be almost entirely taxed at 40% to see it whittled away so dramatically.... particularly if your level of trust in the government is extremely low!
I think he'll have that covered: "Medvedev studied physics and math at a specialized school before graduating early and enrolling in economics and commerce at the Moscow State Institute of International Relations." He's probably the smartest guy, academically speaking, playing professional tennis right now.
