That other driver shouldn’t have cut you off! Your teenager should have cut the lawn or you should have made the cut for the soccer team when you were fifteen.
Your mind doesn’t care what day it is or even what year it is. It dredges stuff up from the past or worries about the future. It has little respect for your emotions and will often provide just the wrong thought at just the wrong time.
It will demand that eclair right after you started dieting or day dream about someone other than your spouse distracting you from the fact that today is your anniversary.