Years ago I ran across aparagraph or two of R Bradbury's, I think from the Martian C. It was along the lines of "The secret? There is no secret—or the secret is to enjoy each moment" etc.- That was the jest of it.
can anyone help me find that passage?

Sounds like something Spender might possibly have said when he was telling the captain the way the Martians lived. Other than that, no idea. Really, that concept is espoused in any number of R.B.'s books.

This might be what you're looking for: "The Martians discovered the secret of life among animals. The animal does not question life. It lives. Its very reason for living is life; it enjoys and relishes life. You see--the statuary, the animal symbols, again and again."
"It looks pagan."
"On the contrary, those are Gods symbols, symbols of life. Man had become too much man and not enough animal on Mars too. And the men of Mars realized that in order to survive they would have to forgo asking that one question any longer. Why live? Life was its own answer. Life was the propagation of more life and the living of as good a life as possible." (The Grand Master Edition, pp66-67) That was Spender talking to the captain. Hope this helps.