Sneaking into the van Gogh museum

My father and I visited Amsterdam (in the Netherlands) during a trip to Europe during the 1990 Passover vacation. During one morning, we went to the Vincent van Gogh museum, and we were let in without being requested payment.

After we did an enjoyable tour of the exhibition, we walked out and noticed that there was a long queue of people for the cashiers on a separate building. While we felt guilty about not having paid, we lacked the time and patience to stand in the line, so we just walked away.