Prior was the only batsman to pass 50 for England during the humiliating ten-wicket loss.
The Sussex player said: "You can spend as much time in the gym and as much time in the nets or on the training ground - but until you're out in the middle, you don't get that ring-ready feeling.
"It's getting used to little things - the nerves, travelling into the ground. I felt, in that first innings, I had to get used to switching on and off again."
The second Test begins on Wednesday in Abu Dhabi.