The fun is in the going.

You keep right along with the procession until old age gets you.

The thing is just to keep it up as long as you can." He swung himself into a sitting posture on the edge of the desk and noted that the slight pucker had not left his partner's eyes.

"What's the idea ?" he wished affectionately to know.
"Oh, nothing much, but I sort of grew up with the idea of Duty--something you had to do because there was nobody else to do it.
You had not only to do it but you had to like it, not because it was likable, but because it was your duty.

It was always right in front of me: I couldn't see over or around it; I just had to do it." "Well, you did it," Lessing corroborated.