HaShem created man with the potential to look at the difficult lot of his fellow man and be thankful to HaShem for all that has been provided to him. Similarly man can look at the giants in Torah and service of HaShem and feel remorse at his own meager spiritual accomplishments.
What generally happens however is the opposite:
Man looks at the wealthy and prays to HaShem to improve his meager lot in the physical world, and looks at the sinners, and believes his spiritual accomplishments are quite lofty.
Rav Steinsaltz goes on to explain that the most fundamental necesity to Teshuvah is to be aware that we lack. If we don't lack, then Teshuvah is impossible. So much so, that even one who hasn't sinned can still do Teshuvah if he finds himself lacking. If, on the other hand, someone sinned but feels as though he lacks nothing, no Teshuvah is possible.