We were making garlands of grass for Ganesha at the temple. Why grass? Grass is what we walk, run, trample on. Yes, it's the humble grass that adorns Ganesha. However, the grass is first washed clean of mud before it goes to make up the garland.
Ganesha accepts the meek, the humble and the poor without reservations. Ganesha also accepts the little mouse that runs and hides in nooks and corners and is despised by all. With his fat belly this god seems to be telling us that none should mock the fat or ugly. Anyone who is egoistic and ridicules the appearance of others incurs 
Ganesha's displeasure - he'd cursed the moon that had dared to mock at the fat Ganesha riding a small mouse and falling all over.
Do not ridicule the modest, the timid, the unfortunate and the unappealing is his advice and he holds a hook and noose for those who ignore this warning. The noose is to goad the unwilling and the hook is to draw him towards himself. Shiva and Parvati remind us their son is the Lord of all Ganas. Ganas are those who are controlled by the five elements -- earth, water, fire, space and air. Ganas cover all beings, right from insects, animals and humans to subtle and celestial beings. So when we bow to Ganapati we honour all the ganas and get blessings from all.
Ganesha's elephant head stands for universal consciousness and knowledge. A small person is the one with ego who thinks only of "Me, Mine, and me" but when the ego is superseded by Brahmn or Supreme Consciousness, then it becomes universal. In this state you begin to work selflessly for others considering them to be part of one big family. You expand in knowledge and love all. The ego dies and you get a new life just as Ganesha got a new life.
Devotees bring coconuts to Ganesha and the priest breaks the coconut in front of the deity, showing that the ego has been broken and we ready for higher knowledge. Devotees tap their forehead with their knuckles as if reminding themselves to be humble and they pull their ear lobes as if atoning for their sins.
Gana or Ganapati, everyone leaves the same way, absorbed in the five elements. Ganesha images, howsoever grand, are submerged in one and a half day, three, five, seven, ten days or on Anant Chaturdashi. A devotee asked the young guru Kanchan Didi, "Isn't it sad and senseless? We make images, decorate them and then submerge them. It's funny!"
Kanchan replied, "Sad for whom? Have you seen a Ganesha or Durga crying because the same devotees who worshipped them lovingly have not only removed their expensive ornaments and clothes but are also pushing them in the water? They undergo this ritual to put sense in us. This is mrityuloka, where everyone has a time limit, so why should one get attached to things, people and situations? If an image obstinately floats, it is pushed down. 'Go, Go', the devotees chant, for the one who clings gets tossed around like flotsam and jetsam. Year after year this ritual is repeated so that you understand that the only source of happiness and sense is God. You are sad because you claim ownership over what is not yours. You think it's senseless because you waste time in meaningless things. You think it's funny because despite getting hurt you cling to people and things desperately..."