Although I have a NEXUS pass, I hate going across the border into the USA. I find the whole process so unfortunate. The level of security is bordering on the preposterous, especially when flying into or through the states.
So it is so refreshing to travel between European countries. In fact, on our way from Luxembourg to Belgium, on a couple of occasions, I took the wrong turn and ended up in Germany for a few minutes at a time. Often the only way to tell was by the more run down buildings and aggressive drivers in Audis with a small D on their license plate!
When we reached Belgium, we did see this border sign, and to let us know that we were truly in Belgium, it was shortly followed by the sign for frittes!