I can give a somewhat trivial example from my experience since it came up today in the context of responding to this specific thread in the forum. I read your response today morning. I wanted to respond to it right away. But I had an appointment a little later in the day. I had planned on doing some household chores before I left the house for the appointment. If I spent the appropriate amount of time which was needed to think and type up this post at that time and make my appointment, I would have to postpone or make shortcuts for the chores. I could leave the breakfast dishes unwashed in the sink and get to it after I came back home from the appointment. And I could take the dog out for a short walk in the neighborhood instead of driving her to a leash-free area where she runs around, which takes more time. I could justify responding to the post and not doing the dishes and taking the shortcut with the dog walking by invoking "higher and better things", since I treat forum interactions as something serious. But in this specific context, it would simply be an excuse to do what I preferred over the daily chores. What I did was to finish the chores with the level of quality that is satisfactory to me before leaving for my appointment. As expected I could not get back in front of the computer until late evening which is when I am responding to the post.
Like I said, it is a trivial example. Some not-so-trivial examples would be people invoking the "higher and better use of energy" argument to forego what their mundane life is bringing to their notice on a consistent basis. Thus we could have someone who is so busy learning and discussing esoteric issues or issues of global importance that he/she neglects what life here-and-now is asking of him/her. Their living place can become a mess because they avoid doing what is needed. Their families may suffer because they are not pulling their weight. And for younger people, they can use the "higher and better use of energy" argument to actually not live their lives by taking some of the unavoidable risks one needs to take in order to go out there in the world and have experiences related to education/profession/relationships and thus learn and grow.
Hopefully the above makes sense. We need to understand the details of a specific situation to know whether one is making the best and most judicious use of the energies and talents loaned to him/her in the moment and in life. It is not about getting it perfect but about being committed to a path of growth which benefits the person concerned, people around him and society at large. OSIT.