As a child and adolescent psychiatrist in Puerto Rico, I always tell my patients that in any situation, no matter how hard or difficult it is, there’s always something positive that we can learn. Now, I know how true this statement really is.

I learned this first-hand when I started dealing with brain tumors in the summer of 2014 -- first as a relative, then as a friend and finally, as a patient myself. Along the way, I developed...