Do you know a Japanese word/expression ” mikka bozu”?
You quit something after (only) three days even if you pledge to do it.
Literally it means a three-day-monk.
三日（みっか）(mikka) means 3 days.
坊主（ぼうず）(bozu) is a monk.
So the story behind this is, you want to become a monk and start training but it is so hard or you are too lazy to continue that you quit after 3 days. Does that sound familiar to you? To me it happens all the time..
How to use this word in a sentence?
I started jogging but I already quit after 3 days.
Make sure you don’t give up after a few days but do your best.