Well, I got another nice surprise this morning, while researching health insurance in the Netherlands. Personally I think insurance companies are the biggest scam of the 21st century, but health insurance is mandatory in the Netherlands and you're doing something illegal if you're in the country without health insurance. It disgusts me that I have no choice in the matter.
The nice surprise is this: since I never unregistered myself as a Dutch citizen, as far as the government is concerned I've been living here in the Netherlands for the past 4 years. Uninsured. Wondering if this was going to pose a problem when applying for health insurance I searched a bit and scared myself with the result: if you've been uninsured for any period of time, you have to pay back the monthly insurance costs plus a 30% fine. For my 50+ months of staying in Japan that amounts to thousands and thousands of euros...
Oh dear. Sounds pretty bad. If only I had unregistered when I left Holland... I called up an insurance company to ask about my situation, and fortunately they were very understanding. They told me that I could send a copy of my job contract as proof that I had been working in Japan as an alternative to citizen registration, and then I could just start afresh without paying any money for the four years that I've been gone. Whew!
On a side note, my natural aversion to insurance has led me to research the possibility of not having insurance at all. This page (in Dutch) tells me that it is indeed possible to escape the mandatory health insurance in the Netherlands if you claim that because of your personal convictions you disagree with the concept of insurance in general. The page further describes that, if, because of your personal convictions, you are not paying money for insurance, you still must 'pay a part of your income' instead, which happens to be the exact same amount as the insurance policy would have cost. This whole insurance business is just too silly for words.