Here's my vacation from H***, and the warning I would give you, is that you learn more about people when you have to travel with them.
A friend of mine was organizing a trip out to the Big Bend in Texas. We would go through Carlsbad Caverns, then head down to the Big Bend, and then back up to Dallas. There would be six of us: He and his son, his GF, me, and another couple. No problem.

(right!)
The first day went pretty much without any complications. We made it to Carlsbad, NM, that evening, got our rooms, and then got up the next morning to tour the caverns.
Again, still not too much of a problem, other than the so-called "friend" I was traveling with happened to be a control freak of the worst order. Come to find out, he had taken this EXACT SAME VACATION two years before (this was in 1989) and wanted EVERYTHING to go EXACTLY as it had done on the trip two years ago (with completely different people, may I add)...all the way down to demanding that we go bowling in Carlsbad, NM, at 10:30 at night!
This isn't a joke. It gets worse.
After we finished the caverns (which we did without a hitch), we set off towards the Guadalupe Mountains and our next stop which happened to be McKittrick Canyon. I thought we were going to stop there for lunch. Stuart (my "friend") demanded that we hike the full 2 1/2 miles into the canyon. OK, guys, now this is about 1:30 in the afternoon in mid-June, and the temperature is already soaring towards 110. There isn't a dry place on us, and we're desperately seeking shade. So I told him that he could hike on in there, but I would stay back at the shelter (reasonable enough.) The others quickly assented to my suggestion.
Stuart proceeded to throw a tantrum (he was 29 at the time), screaming, bellowing, cussing, and finally stalked off into the canyon by himself. Nancy (his GF) decided to run after him and see if she could reason with him. Greg, Anne, and I debated on whether we should drive off and leave him, but we decided not to because of Nancy, whom we liked. So we waited there in the sweltering heat for him to get his head cleared and come back (about an hour and a half.)
The next day, we were still en route to Big Bend, but we decided to stop and cross the border to Ojinaga, Mexico, so Stuart could buy some tequila. Stuart didn't want to take his car across the border *sigh* so we had to trudge over the long bridge over the Rio Grande to get there. On the other side, there was the customs office, a small duty-free liquor store, and some souvenir shops. The town of Ojinaga itself was set back another 1 1/2 miles (at the very least).
So Stuart is about to purchase his liquor, when a man (local) in the store persuades him that there's much cheaper liquor prices in town. Well, guess what. All of us have to trudge after Stuart the 1 1/2 miles into Ojinaga, again in 110 degree weather, and to make matters worse, they were tarring the main road into town.
To make a long story hort, I got sick. I started vomiting and got pale and shaky (classic heat stroke). How I made it back across the border, I'll never know, other than I was 25 at the time and had more stamina than I do now. All I could do was lay in the back of the van and wish that I were dead.
Oh...and the best part? The "cheaper" liquor that Stuart went for was 8 pesos cheaper than the one he would have purchased at the border...a difference of about 1/16 of a cent in American currency.
It took me the rest of that day to recover. I missed pretty much the entire drive from Presidio to Big Bend, which I have been told is a marvel of natural beauty. Maybe I'll get to see it someday.
So we fetch up in Big Bend that evening. I'm still recovering from heat stroke, but doing a lot better, but I'm still pretty dang weak and shaky. So as soon as we make camp, Stuart INSISTS that we go hiking into Boquillas Canyon. I said "not no, but H*** no!" and he calls me a "wuss."
That's when I broke. I called him every name in the book but a healthy male, and told him to get his carcass into that canyon and that I hoped he rotted there and that the vultures picked his bones, and after they did I'd get his freakin' skull and use it as a candy dish on my coffee table at home.
We didn't speak for the rest of the trip, which was fine with me. I rode back to Dallas with Greg and Ann (the other couple) who were as outdone with Stuart as I was, and I think we spent most of the trip complaining about him and then laughing about it, which helped all of us get over that nightmare.
That was the end of that friendship. Stuart and I have never seen each other since (that's been 12 years) and I don't feel that I've lost anything. I have no regrets about that. But you can know that from that point onward, I made danged sure that I knew who I was traveling with, inside and out!
I've had no troubles on vacations since that time.
Cheers,