Models and athletes can't do their jobs anymore as they age; modelling is all about the beauty of youth and most sports with pro atheletes do a lot of physical damage that adds up over time.
Our jobs aren't like that at all. We may not be able to handle 48-hr caffeine-fueled marathons anymore, but our experience tells us that those are a bad idea anyway, and we wouldn't do them even if we could. That experience is valuable, giving us insight and true productivity, and lets face it the job is sitting at a desk... we can do that well past retirement age, since we'll be doing a lot of sitting around anyway.
Our jobs aren't like that at all. We may not be able to handle 48-hr caffeine-fueled marathons anymore, but our experience tells us that those are a bad idea anyway, and we wouldn't do them even if we could. That experience is valuable, giving us insight and true productivity, and lets face it the job is sitting at a desk... we can do that well past retirement age, since we'll be doing a lot of sitting around anyway.