I live in Nijmegen, the Netherlands. I don't go to Amsterdam much though - them there westerners don't really agree with me. Of course there is much to see there and especially for foreigners who aren't used to having such a large red light district in the middle of the city. Last time I was there, it was to show an American lady around. Amsterdam has a decent naval museum which we visited back then, but there isn't so much to see about the World Wars there. Of submarine note, the war and resistance museum at Overloon (in Noord-Brabant, about 2 hours away from Amsterdam) has a German miniature submarine of the Biber class. It's now well-preserved inside ever since the museum merged with the Marshall museum a few months ago.
About 2 years ago, a miniature sub of the Seehund class was found on the beach with its torpedoes still in place! Don't know what happened to the sub after the torpedoes were removed and blown (they must have been blown somewhere).
It sounds like you had a great trip! Italy, Belgium and the Netherlands. You saw most of the major cities in Italy and Belgium yet mysteriously confined yourself to Amsterdam while going Dutch...
May I ask what you found so much fun about Amsterdam?
Kind regards,
Eichenlaub