Self inductance question?

why does time varying the intensity of a current on a conductor result in a 'resisting' magnetic flux? in other words, why does applying an alternating current to a conductor induce a flow of current in the opposite direction of that which created it? (i can understand in somewhat analogously of inertia, in such a way that a current in motion wants to stay in motion and a current at rest (a not current) wants to stay at rest). but why?