Breaking -in: the real story

I'm sorry if this topic is repetitive. I've looked through the search menu and have, frankly, been a little confused. Some have said that you should just drive no problem, others have said go highway, and still others have said to do stop-and-go city driving. I've even read the posts that have said that Honda has 2,000 miles on the engine prior to your purchase (hmmm...). We're buying our Odyessy 3 hours away, highway driving. I had no thought of driving it home until I talked to my brother who said I should be careful about how we drive the car during "the break in period." I am not a car expert, but is this a real issue or just something made up that you can blame yourself for in the future if anything goes wrong?