On "Kathy Griffin: My Life on the D List" last night, Kathy was in Canada to do a show, and she was nervous. She pointed out that she's always nervous before a show, but in fact, she hadn't done any standup in three weeks, and she was more nervous than usual.
Three weeks? A pro like Kathy Griffin gets nervous when she hasn't performed in three weeks?
The only way to stay on top of your game is to stay in the game. The more you speak, the more often you take the opportunity to get in front of an audience, the more you hone your skills.
Just like an athlete, a performer can lose ground when there's no opportunity to practice. You have to stay warmed up, flexible, in the zone.
Take time off, and you might get rusty. You might lose your rhythm.
If you're doing the same presentation every time, taking a break is a nice way to freshen up your "show," resist the temptation to start memorizing, and give your brain a rest.
But don't take too much time off. Stay fresh, but stay in the flow. Try not to go too long between speaking engagements. The more you speak, the more you learn and the more you grow!