Saving money can lift your spirits and fill your wallet. After a while, though, pinching pennies may start to hurt. Welcome to "frugal fatigue.""It's a very real concern," says James E. Burroughs, a commerce professor at the University of Virginia in Charlottesville, who specializes in consumer behavior."I think it speaks to the challenge," he says. "It's very important for people to become habitual in their finances." ...Strategy 2: Take charge, and frame it as a positive.When fighting frugal fatigue, remember to remain upbeat. "Being optim...