Do you know how long a year takes when it's going away?' Dunbar repeated to...

Do you know how long a year takes when it's going away?' Dunbar repeated to Clevinger. 'This long.' He snapped his fingers. 'A second ago you were stepping into college with your lungs full of fresh air. Today you're an old man.'
'Old?' asked Clevinger with surprise. 'What are you talking about?'
'Old.'
'I'm not old.'
'You're inches away from death every time you go on a mission. How much older can you be at your age? A half minute before that you were stepping into high school, and an unhooked brassiere was as close as you ever hoped to get to Paradise. Only a fifth of a second before that you were a small kid with a ten-week summer vacation that lasted a hundred thousand years and still ended too soon. Zip! They go rocketing by so fast. How the hell else are you ever going to slow down?' Dunbar was almost angry when he finished.
'Well, maybe it is true,' Clevinger conceded unwillingly in a subdued tone. 'Maybe a long life does have to be filled with many unpleasant conditions if it's to seem long. But in that event, who wants one?'
'I do,' Dunbar told him.
'Why?' Clevinger asked.
'What else is there?