Memory Stick Miracle

Sometimes people surprise us. Sometimes even thieves do the unexpected. Consider this from a report titled Swedish professor rejoices over laptop thief's memory stick miracle:

The professor, who wished to remain anonymous, is one of the most successful in his field, according to the newspaper.

Having recently had surgery, the professor could not be bothered to drop off his backpack in his apartment before first going to the laundry room.

He instead left the bag behind a door in the stairwell, thinking it would be safe for a few minutes.

But when he returned a short time later, the bag was missing, along with the computer, keys, calendar and other documents inside.

The professor was most upset by the loss of his calendar.

"It is my life. I have documented everything in it that has happened in the last 10 years and beyond," he told the newspaper.

He then called the police to report the incident and blocked the credit cards which were also in the bag.

But when he went down to the stairwell a short time later, he couldn't believe his eyes.

"The backpack was there again. With all the papers, calendar and credit cards. It was just the computer that was missing," he explained.

Now if this isn't an amazing turn of events in itself consider this:

About a week after the theft, the professor returned home to find an envelope containing a USB memory stick which had been taken along with the computer.

The professor was shocked to discover the thief had copied all the documents and personal files from his laptop to the memory storage device, a process which likely took hours.

I do wonder what motive the thief had for stealing the professor's computer? And what would cause him to risk returning the backpack to the scene of the crime? And why would he further risk capture by delivering the memory stick to the professor's apartment?

Puzzling questions. Anyone care to offer an answer? I am simply stumped.