I was having trouble with my computer. So I called Eric, the 11 year old
next door, whose bedroom looks like Mission Control and asked him to come
over. Eric clicked a couple of buttons and solved the problem. 
As he was walking away, I called after him, '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.'
Eric 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 down: I D 1 0 T   

I used to like Eric, the little bastard.