Travelling & taxes?

This is just something I've been wondering about (I have a lot of time on my hands); being 15 I don't know a huge amount about taxes due to... not having to know a huge amount about them yet, but as far as I know you start paying them to your government when earn a certain amount of cash, right? So what about those people who travel a lot (not gypsies, just people with wanderlust I guess)? Do they pay taxes?

Generally, a determination is made as to where someone is domiciled and where one is currently.

If I visit a country for 183 days or more during a tax year, that country will want to treat me as a resident and tax me accordingly. (If I visit a country every year, it can take less days.) The same is true of regional subdivisions.

Some levels of tax have reciprocal agreements. That is, if both the US and the UK tax you on the same income, one of the countries will give you a tax credit for the some or all of the taxes paid to the other country.

Ask, yourself, if the government does not know where you are how can I tax you. Why do you think ,the travellers always ask for cash, when they are tarmacking your drive and do the odd jobs and then disappear and go and trespass some where else.