Given that a salary of $101k in Europe is unlikely, and that taxes are almost always higher in Europe than the US, you do not need to worry about paying income tax to the US.
You do, however, need to file a tax return.
I don't support these policies, but I wanted to clarify things for people who could get scared away by your comment. It really isn't that bad.
When U.S. Citizens Living Abroad Owe U.S. Tax: http://www.nolo.com/legal-encyclopedia/when-us-citizens-livi...
Still, it is of course painful. As someone in the reverse situation (foreigner in the US), I had to pay income tax to Norway for the first three years after moving, with US taxes paid being deducted from what I owed. On the other hand, I did not need to pay the Norwegian equivalent of social security; income tax only.
(Of course, the Norwegian tax system is also 100% digital, with very simple forms that are already filled out for you based on what your employer etc. have already reported to the authorities; the US stuff was just a small additional form. So in reality the painful part was and is the US tax return, which is ridiculously antiquated and complicated and involve lots of paperwork, especially when you have foreign bank accounts.)