@longer I've simply never declared my income. Everything I buy is through a third party. My bank account is shared through my parents'. As far as the gov's concerned, I'm an off-the-grid neet.
I followed after my friend's mother's footsteps. She's a college professor who just never thought to declare taxes and by the time a friend mentioned it to her she's been 30 years late.
My mom's friend is kinda like that. Unfortunately she lives in a strict welfare state that cracks down on non tax payers. Well, unless they're giga rich then they just hide away in Switzerland or a similar country.