A rematch asks whether the first outcome deserved the meaning attached to it.

A rematch tests whether the first result meant what everyone said it meant. One outcome supports a large story about who is better, and playing again can reveal that story to have been an interpretation of a single day. The willingness to repeat is what separates evidence from anecdote.

Apply the same standard to conclusions you have drawn from single events. One bad presentation, one difficult meeting, one failure at something. Would it hold up on a second attempt? Often the honest answer is unknown, and the only way to find out is to go again rather than to accept the first result as a description of you.