Only to think of the drastic changes to technology by the time any of us are that old..
Something else to keep in mind: Not only didn't todays 80-year-olds grow up with computers, the vast majority of them also never used them in the office since most companies didn't actually use computers before these people retired. Don't underestimate how recent the whole 'computers on every desk' scenario actually is.
The more time passes, the more computers will just be a way of life for everyone including the very old.