You will actually be doing him a favor by telling him the truth. Getting hurt or taking it as a part of life and moving on is his choice to make.  There is no other way to go about it because you

Depends on how one defines maturity.  It is very subjective. Each and every person's expectations of mature behavior is different I feel. In terms of being able to understand and realize the emotional

Great tips. Keep up the great work. I would just like to add that when it comes to physical exercise, we just have to make sure that we breathe through our nose(not gasping for air) and increase our capacity