How do atoms lose their induced dipole?
The said lesson tends to oversimplify things to the point of getting them downright wrong. Atom dipoles do not line up with each other. They are way too weak for that. Should it be according to your description, they would indeed line up all in one direction and stay locked forever, much like magnetic particles in a magnet.

Now, I brought up the magnetic analogy because it is much better known than the similar electric phenomenon, called ferroelectricity. That's where your explanation is precisely right. Compounds that exhibit ferroelectric properties, once polarized, never lose their dipoles unless you force them to. But they constitute just a tiniest minority of all compounds.

What happens in the rest of them? Well, the molecules turn this way and that, atoms bounce and wiggle, spontaneous dipoles arise every now and then, only to vanish almost instantly. But the position where two neighboring dipoles are aligned in the same direction is energetically favorable, so they spend a little more time in this position than in the opposite. And that's what we call induced dipoles, dispersion forces, etc.

So it goes.