Live. Love. Ride. Milk.
I really think it depends on the goat themselves. Some goats can go for YEARS and with little or no training be shown again and others if you give them a week off you have to pretty much start over again. You just need to learn what your goats need to keep in shape. I have 2 does(2 of my best btw) who if I take them to a show and then give them a break for 2-3 weeks until I start getting ready for the next show I must almost reteach how to walk. Usually they remember how to stack up, but sometimes not. On the other side of that I have a 6 year old doe who was last shown as a yearling, but I could still go into a showmanship class with very little training with her and she would stack up fine and stand with no problem. She hasn't been shown in 5 years nor has she been worked with so that goes to show you it depends on the goat.