[rzodkiew]

It's most likely connected with an ability to create models of reality (or intelligence). If you want to achieve certain change in environment, you need to be able to speculate on the state of the future and how to achieve it. In order to do that, one needs to be able to access the memories and locate some actions and consequences they had. Consciousness can be then seen as a root cause of those actions, especially when modelling the future.

Imho, self-control is about the energy expenditure and the fact that brain is optimising for the energy conservations. Habits, addictions and other available models of reality are cheap to access. Conscious self on the other hand requires much more energy to create new models of reality, therefore your brain will try to avoid them as much as it can.