This is why we need to live for something other than ourselves. Family is the usual end of such a life, for most people. Making the future you'll never see.
Discussion
I was thinking about that, with the gym thing. Everyone wondering why you don't go to the gym, every day, while renovating a house and caring for your family, and walking and working outdoors.
My dear, sweet summer children:
The gym only exists to mimic the physical movements required to live a full, productive life. It is not an end, in and of itself.
Yes! I certainly *want* more time in the gym, or more time to go on jogs, because that kind of exercise can help me stay fit for the physical activity I actually want and need to do. But like you said, it's not an end in itself, and so it falls lower down the list of priorities.