It's absolutely true.... and the "I don't like you" part tends to fade a bit the further you get from your academy time.
At any service academy, you'll see the best and worst (well maybe not the WORST, but certainly nothing they'll be proud of) in people, and they'll see the best and worst in you. Some people will rub you the wrong way, and you'll rub others the wrong way. But.... like family, when push comes to shove, you'd defend them. You'd let them crash on your couch if they needed it while they were in town. Years down the road, you'd sit down for lunch or a drink, and just talk.
I had about 200 classmates at CGA. I didn't like all of them. In fact, at the time, some of them I really didn't like and some didn't like me. There are things I did, ways I handled situations as a cadet, that today, at age 31, I would have changed. And I think the more I've realized what I could have done better, the more forgiving I've become of my classmates I didn't like at the time. I wasn't as perfect as I thought I was and they weren't as bad as I thought they were.
And on the flip side of the coin, you will also make some of the best, more reliable friends of your life. Often those friendships will eclipse your friendships from childhood and high school (which tends to be the case in college, anyway).