A secret lair has a code to only allow members to enter. The person wanting to enter says a random number, then is told a number in response. In order to enter they must say the correct third number. Here are sequences that allowed entrance.
Five because s-e-v-e-n has 5 letters. The first number can be anything, the second number is the number of letters in the first number, and the third number is the number of letters in the second number.
Getting older. Sad but true, and there’s nothing anyone can do to stop it. If you thought of breathing, it’s not entirely accurate because not everyone takes a breath at the same time. Living is an arguably suitable alternate answer as well.