What just happened? Could not shift out of 1st gear

My 98 Passat (82K miles) did the strangest thing today. I left a parking spot and the automatic tranny would not shift from first gear. I tried switching to the manual setting, but it wouldn’t shift out of first from that either. Eventually, with some frantic back-and-forth shifting in manual mode, it did go to second, and from there on the tranny has been working normally, including in automatic mode.

The only unusual thing I did before this episode was to park in an awkward spot, so I had to do some back-and-forth from reverse to drive.

Any ideas what just happened? Is this just annoying, or should I be worried? If I should be worried, should I be worried to the tune of hundreds, or thousands of dollars?