Today's idiom is another good one you can use every day.
"I can't help it"
It means that you can't change the situation.
A. Nancy, stop sneezing!
B. Sorry Bob! I can't help it . Allergy season.
A. Do not be so shy.
B. I can't help it . It's my character.
A. You were late this morning.
B. I couldn't help it. There was an accident on the Yamanote line.