Psychologically you've changed. Test might help but ultimately the enthusiasm and recklessness of youth burns out, and is replaced by wisdom, emotionally maturity, and yes, becoming ever so slightly jaded.
That's why death is a necessity, ultimately, no matter how wonderful your life is, the fragile ego we possess becomes fatigued by the relentless onslaught that conscious perception provides. The world turns and the light we possess, in some ways, grows dimmer. That's why it is so important to treasure every breath, every fleeting moment.
The beauty of life is in it's transience, take nothing for granted, harbour no regrets, and waste no time mourning past glories.
We are like the fire bird, burning brightly only to be reduced to ashes, but one day to be borne anew (forgive for posturing in such a pretentiously egregious fashion - i'm quite drunk tonight).