Habit enlists the power of inertia, for good or ill. However much the fact may offend our vanity as reasoning creatures, the vast majority of our habits "are created" without our conscious intent. As for humans, so for other animals. The unconscious mind is tenacious and indefatigable (sleep is for sissies!) in its quest to make just enough comparative sense of incoming stimuli to determine how we should act in order to get what we want and avoid what we don't. (How is this like or unlike a situation I've seen five or five thousand times before?) What it lacks in nuance it more than makes up in speed and confidence. If the unconscious mind has lit upon a strategy it really likes -- and likes more every time it repeats it, familiarity in this case breeding affection -- the conscious mind is generally left to mop up after the fact. (Oh, I totally meant to do that, and here are twenty reasons why...) Or to boast about its superior refinement and sophistication. Indeed, in the case of humans, the conscious mind sometimes seems as tireless in the task of self-glorification as the unconscious mind is in the humbler but more critical task of self-maintenance.
We might have a great deal more success in creating new habits and dismantling old ones if we had more respect for the unconscious mind, if we treated it with the courtesy and forbearance that elders should always command from the young. That upstart frontal cortex flatters itself that it knows what's best, but it can't get anything done on its own. It needs the collaboration of older and more resilient structures. It can only lead -- if it leads at all -- by encouraging consensus. Consciously adopted habits are one form that consensus can take.