Time is All You Need
The only truly finite resource and thus the most valuable one. All other resources can be derived. Except meaningful relationships. But even those require time to deepen.
Within the trifecta of money, knowledge, and time it is obvious which one is the most valuable. Generally, one must use two of the three to obtain the third. So the young trade time and money for knowledge, or time and knowledge for money. However, once old, people would give often anything just to be young again, to regain the resource they had spent their whole lives trading for something else.
The old may use their money and knowledge to save time, but once spent, time is gone forever. Of the three it is the only truly finite resource. So it's a tragedy that while the young are so rich in time, such fortunes are so easily squandered.
We even have a phrase for this: "killing time". Time is a noble maiden. Treat her with honour.
It's my opinion that one of the most virtuous things you can do is save people time. Health is an obvious one, but think of how much time has been saved by faster transportation methods. How many more hours people are now able to be spend with people they love, doing things they love.