If it happens now, it won't happen later; and if it doesn't happen now, it will happen later; so the important thing is to be prepared.
In this sense it is possible to understand that he says it doesn't matter what time it will happen, the person must be well prepared for when it will actually happen. However, for the events in our lives we can never predict all of them or when they will come, happen, it is important to know how to deal with them when the time comes.