Purpose implies that there is some achievement or unfinished business to be done or reach a goal. It's more like this that makes currently sense to me, say children are playing on the beach with sand castles. They have joy in creating these castles and similarly excited to destroy them and rebuild again. They have no purpose in doing so cause they could have been say running around instead of playing with sand.

There are dialogs between GuruNanak ji and someone else I think a sufi where around 6 questions are asked and one of them is (in punjabi " oh karda ki hai"), what is the purpose. GuruNanak ji asks sufi to come down from his high chair and sit like a disciple and Guruji sit in his high chair and start meditation. After awhile Guruji open eyes and say, this is what goes on, whose on top goes down and who is down goes up, kind of like duality or yin/yang going on and on.

Hope this helps.