“wool-gathering”

When someone says that you have been wool-gathering, what he means is that you haven’t been concentrating on your work; you have been daydreaming.
*The professor’s talk was really boring. I found myself wool-gathering. *Divya, your exams start the day after tomorrow. Stop wool-gathering.

This is an expression that has been around for several centuries. As for its origin, it comes from the world of sheep farming. In the old days, when farmers allowed their sheep to graze, they always sent a couple of women or children along with the animals. When sheep grazed, sometimes tufts of wool got caught in the bushes and on the branches of trees. It was the job of the women/children to gather the wool and hand it over to the farmer. The original `wool gatherers’ were actually gathering wool! Since the job of wool gathering didn’t require much concentration, it was possible for the individual to let his mind wander — in other words, he could afford to daydream! Hence, the activity of `wool-gathering’ became associated with daydreaming!
Source:  ‘Know Your English’ Series – The Hindu Daily, Sept 19 , 2005.