The endeavour to learn as much as possible from life.
Nothing goes by us without giving us a chance to gain experiences that are useful for life. If one has done something wrongly or imperfectly, that becomes a motive for doing it rightly or more perfectly, later on.
If one sees others doing something, one observes them with the like end in view (yet not coldly or heartlessly). And one does nothing without looking back to past experiences which can be of assistance in one's decisions and achievements.
One can learn from everyone — even from children if one is attentive.
This exercise is called:
(Remembering what has been learnt from experiences.)