is success necessary for happiness?

 no. it's perfectly normal to be happy pursuing a higher goal. actually, i'd argue that the quest is more fulfilling in itself than its intended result. after you've attained what you were after, you don't achieve happiness, only satisfaction. but satisfaction is a flitting feeling, and if you don't have further aspirations in life, you'll sink into the inertia doldrums. after getting to the peak of a mountain, start climbing another.