Time

Anyone who is serious about improving the chances of enjoying life returns should plan investment of his time with no less, in fact with more care and vigor than that of his money.

The fundamental concept is the same: Limited resources should be deployed where, given ones best judgment, the best returns could be most probably generated - taking due consideration of the opportunity costs concerned.

While clever investments of money may generate more wealth, shrewd investments of time may generate returns not necessarily - or not just - in momentary terms, but fulfillments in terms of satisfaction and enlightenment to various extent. But the big difference is that even the shrewdest investment of time will surely not generate any time in return, not even the slightest split second. Every tick of the clock is a second gone which will never be returned.

Plan wisely to invest it for future returns or consume it for immediate satisfaction, just don't waste it away.