If there is no self, why do anything? My limited understanding of Buddhism has already helped me in many ways and I am very glad to have found it. 

With that said, I have always wondered about this title question. If there is no 'I', then why do 'I' do anything? If we can consider ourselves to be just part of everything else, where does the motivation to do anything come from? Surely we admit that there is a self whenever we perform an action (and thus reveal a motivation that must have originated from a self). If there truly is no self, surely we would all just freeze motionless, die and return to nothingness. 

Apologies if this is an ignorant question. I am still feeling my way around this whole concept.
It essentially doesn't change anything. If you look hard, that "I" was always an illusion. No matter where you try to draw a boundary - it is artificial:


Does the body belong to the self or not? How about that constant flow of matter and energy in and out - at what point does it even belong to the body?
Do thoughts belong to the self or not? You are hopefully aware how much of your thoughts are triggered by others, or even just repeat outside influences. Often they are even rationalizations of what you just did for other reasons.
Do feelings belong to the self or not? Much of these are determined by past experiences, your situation, even medications, weather, food.


So, to keep up this delusion of an "I" separate from the rest of the world requires carefully ignoring all things saying otherwise, which is stressful, even harmful to keep up. If you let that drop away, you'll function as you always did, but with loads of more peace. Don't worry - if this body is hungry it will eat, no matter whether you create such mental complications around that process - or not.