Spending on your development is one of the greatest investment you can ever do as a person,Infact,the aspect of personal growth is all that really matters in this life,we cannot do well in life without you pushing yourself and trying to grow or develop from time to time.The momentary pleasure we get will surely fade away and if we aren't careful,that pleasure is what will bring you down.
Therefore we must try to balance it up,a little enjoyment,accompanied with a proper account of how you are developing in your personal life.