Mom often quoted,'Face is the index of character'. I have seen the world a little more too closely to believe in that anymore. The devil can appear with the sweetest, most shy smile, then charm you and rob you of all your happiness. And an angel might look the devil, but he will help you like a guiding star.
What do I look for then? 'The eyes, the windows to the soul.' Some eyes have sparks of eccentric genius in them, some look tired, some sparkle with the hope of a better tomorrow, and some are visionless, confused, lost in the roads of desultoriness.
The day I truly grow up will be the day I can be inert to everything around me, and filter in only happiness, no matter what. Spiritually, that would be day of my Salvation. What the Vedas conceptualized as Moksha, or the Buddhists called Nirvana - the ultimate liberation. That day, I guess I will have the calmest pair of eyes.