Readiness is a lifestyle. You don't have to check everything everyday or not do all kinds of good things but it is something you have to spend a little time on from time to time.
Big disasters don't have every day or even every month, but when there is one or the weather report is threatening, it is a good idea to evaluate what you have on hand and what you might need.
At least check your stores once a year. Daylight Savings Time is coming up on the 14th and that is a good time to check over things.
It is also a good time to improve one aspect of your disaster kit. I talked about a Layered Approach to Readiness recently where you go for Good, Better, Best solutions. Look at your kit, is there something good that can be made better? Now is a good time to improve it.