It does say that we knock on Hashem door like paupers. There is certainly truth to the idea that a paupers who have nothing ask from the depths of their heart because they are truly pitiful and are truly desperate.
I wanted to add to Lev Aryeh that Davening is realizing how great Hashem is and how much you lack from not being truly close and intimate with Him and expressing your longing for being locked in a close knit and intimate relationship with him that you always feel His love and kindness regardless of what happens in your day to day life.