Some of the most invigorating people we find are those who have had some sort of struggle in life; [not like money or anything materialistic. Indeed, poverty & getting out of it is a challenge of its own], but what I mean is like something that draws up a challenge & you have to face it head-on. It can be anything. Through fighting & overcoming it, you can almost sense their nature becomes preeminent as if their will changes, slightly offset to the ordinary if I might say but still ever present, only now with a powerful-like aura around. Unknowingly it's there & it happens, somehow rare to find, some may never find it throughout their lives but it turns out to be one the most admirable qualities to notice in a person. Not to say that I'm judging or like there's a specific category spoken here about. It's just you can see it in their eyes & know it's full of life... they needn't be successful, rich, poor, adventurous, dull or in anyway categorised specifically to find this. They just have it in their eyes & it SHOUTS out its strength clearly! I've heard that eyes are the windows to the soul & began to believe it through my own observations. Purity, anger, despair, happiness, all but everything can be seen through it which is a reflection of the soul. The best human qualities are those pure hearted, it brings about a reason to be alive & to appreciate life no matter what type of you're living. Personally, I believe it's a key, everyone on their own needs to find the door it opens...