And as opposed to Saint Kar, I would answer "Achievement" not defined solely as winning. (So I like the distinction she made, even though I liked the reclassification. ) Achieving what I set out to do, striving to my goals and beating my standards.
It's not achievement really, nor is it personal pleasure...
The main motivation is to be what I was put on this earth to be (whatever that is).
Accept the past. Live for the present. Look forward to the future. Robot Fusion
"As our island of knowledge grows, so does the shore of our ignorance." John Wheeler
"[A] scientist looking at nonscientific problems is just as dumb as the next guy." Richard Feynman
"[P]etabytes of  data is not the same thing as understanding emergent mechanisms and structures." Jim Crutchfield
I am caught between my desires and my ideals. One moment I follow my ideals and the next I am overcome by my desires.
I am blown hither and thither - first by one and then by the other. It is becoming obvious they don't talk to one another. In fact they barely acknowledge one another's existence.
They are like wilful children I am taking out on a walk. "Now, now", I say, "little birds in their nest should agree". But they look at me like I am a Dodo, and keep pulling in different directions.
In some ways they are comical as they are both so determined to get their way and yet are so blind to one another. They are truly like children.
But what would I do without them? Desire give me pleasure and Ideals tells me what's best. You would think that together they would provide me with the best pleasure, wouldn't you? But oh no - one is constantly trying to replace the other. Each is constantly trying to take over the whole world. But there is only one world and two of them. Simple arithmetic seems to elude them.
I have taken them to obedience training school but the therapist just seemed to encourage them. Even therapists seem to be at a loss with desire and ideals - I guess they have their own to worry about.
Sometimes they drive me ragged and sometimes they wear me out - but they are all I have. What can I do with my own children?