Different people retire at different stages but generally, there is such a thing called retirement because our body has reached a certain level of incapability. So you bring your work down to a lower level simply because if you push it beyond that, you may "retire" in a different way soon! Once you retire, there must be a shift of focus from economic and family concerns to something more spirituality oriented. The physical body has come with an expiry date.
So it is time you activate the other aspect which goes beyond this physical body. Everything becomes meaningless and burdensome when the body is threatened and begins to creak and groan. But if you have tasted something beyond the physical body, old age will not be a problem, it will be a blessing.
So once you reach a certain point in your life, you must allow at least a certain quota of your energy and life in that that direction. If you put the whole of your life and energy in that direction there is nothing like it, but at least a little bit of your life should pursue that.
If you are a keen observer you should have done it right from day one as you are born there is a reminder of your expiry date. If you are not such a keen observer, by the time you are fifty there are sufficient reminders. Old age just won't matter if something within you is very vibrant. When the moment of death comes you can smile and go without any sense of loss because it is not a loss. If life happens, death is a natural process. Being afraid of a natural process is unnatural. This fear has come because of a certain sense of ignorance and unawareness. We are not in touch with reality and we have gotten deeply identified with this body.
This has happened because we have not explored other dimensions. That is why often, experience of life leaves most people hurt instead of wise. No matter what kind of teachings other people give you, whether somebody tells you that you are Atman, Paramatman or whatever else, if your experience is limited to the physical body, the fear of losing it is natural. If we had explored and established ourselves in other dimensions of experience, the body would not be such a big issue. It becomes an easy thing to handle. Life or death won't make such a big difference.