He said,The last time I took the umbrella,I left it at a restaurant.”She said,”Put a rubber band around your finger to help you remember the umbrella”He said,“The last time I did that,I forgot to remove it and my finger got all puffy. I could’ve lost my finger.”She said,“Tie a string around your thumb. That’ll remind you to remove the rubber band.”

Why?!? Why he gonna remember if he tie a string around his thumb in addition to put rubber band around his finger?

Are the rubber band and a string attached each other?

Is that a kind of mischievous in the English spoken countries?

It's just a little bit of humour.

Do D to remind you to do E. Do C to remind you to do D. Do B to remind you to do C.

Do A to remind you to do B.

Don't you find that a little funny?

I see..Now I understand. Thank you for replying.