I was having trouble with my computer.   So I called Richard, the 11-year-old next door, whose bedroom looks like Mission Control, and asked him to come over.

Richard clicked a couple of buttons and solved the problem.

'So what was wrong?'

He replied, ''It was an ID ten T  error.'

I didn't want to appear stupid, but nonetheless inquired, 'An ID ten T error? What's that--in case I need to fix it again.'

Richard grinned. ''Haven't you ever heard of an 'ID ten T  error' before?'

'No,' I replied.

'Write it down,' he said, 'and I think you'll figure it out.'

So, I wrote it down...