Why do I always get sick on holiday?

You treat vacation like a job

Too much planning and the structuring of activities as things that you “gotta do” while on vacation can turn your leisure time into a job, according to Tinsley—and a rigid schedule doesn’t bode well for stress levels. “On vacation, a person can become goal-oriented,” adds Tinsley. Focus on one main goal a day you’d like to accomplish, instead of a lot of little activities to check off the list.