The topic always changes. You miss your chance. It bugs you so much that you hang onto the thought for weeks, months, or years, and bring it up promptly at the next opportunity.
“We talked about banana peels four years ago?”
“Almost five.”
“And, you waited for it to come up again to say that banana peels are used in water purification?”
“… yeah?”
“…”
It took me three tries to not read it as “sugary”.