I recall a tower controller at the aerodrome I was instructing at, who was bought some introductory flying lessons by his wife, as he had always wanted to try flying.
His first flight and unlike most students at that point he said he was happy to make the radio calIs (and I assumed radio was not going to be a problem) but... right from the taxi call he got it wrong, said things he didn't need to, missed readbacks, and got it all backwards (and was given lots of attitude in the responses from his mates in the tower who knew it was him, "ABC say again aircraft type", "what are your intentions", "ABC I require read back of..." etc etc as well as them adding in some additional curly requirements to make him even more miserable
)
He said afterwards he assumed he would be fine but because all his experience was from the ATC side, when he went to do the aircraft side of the radio he got himself all out of order.
Worse thing for him was after the flight his shift in the tower started where he continued to cop curry poor bugger.