What was your first RV noob disaster (or near disaster)?

The first summer we had our brand new Autumn Ridge we were traveling down a 4 lane state hwy and I was in the inside lane from passing another vehicle. 2 cars a fair distance in front of me turned on the turn signals for turning into a restaurant and they had a clear road to be able to turn with no problem. First car turned into the driveway.....and STOPPED (he had no reason to stop) so the other car could not turn in. Instant panic stop for me.