A couple in their nineties are both having problems remembering things. During a checkup, the doctor tells them that they're physically okay, but they might want to start writing things down to help them remember.  

Later that night, while watching TV, the old man gets up from his chair. 'Want anything while I'm in the kitchen?' he asks.  

'Will you get me a bowl of ice cream?'  

'Sure.'  

'Don't you think you should write it down so you can remember it?' she asks.  

'No, I can remember it.'  

'Well, I'd like some strawberries on top, too. Maybe you should write it down, not to forget it.'  

He says, 'I can remember that. You want a bowl of ice cream with strawberries.'  

'I'd also like whipped cream. I'm certain you'll forget that; write it down.'  

Irritated, he says, 'I don't need to write it down. I can remember it! Ice cream with strawberries and whipped cream. I got it, for goodness sake!'  

He toddles into the kitchen. After about 20 minutes,  the old man returns and hands his wife a plate of bacon and eggs. She stares at the plate for a moment.

'Where's my toast?'