I read about this topic on the kellymom website and they said something on there that made sense to me and has always helped me remember how it works.
They said just like a faucet, it takes a few minutes when you first turn it on for the hot water to come out (cold water, foremilk--hot water, hindmilk). After awhile, when you go back to that faucet to turn on the hot water, it is there faster, almost as if it "left off" where you had it last. So by that, my understanding is that once baby empties one breast and starts on the other side and only nurses for a minute, when you start on that side next time around, it won't take *as long* to reach the hindmilk. Almost as if it starts where you left off, like the faucet. Clear as mud, right!
That's just what I read and it helped me understand a little better. I don't think our babies are getting as much foremilk and not enough hindmilk as we tend to worry about.