After my first few crash landings I had three Kerbals stuck on the Mun, pretty close to each other. When I actually made my first successful landing, it was way too far away to get them, and I had to go floating around the Mun trying to get to them. Well, when I finally did, not only did I run out of fuel, but I realized my ship only had ONE seat! So I deleted the whole game and started over. I know, I know, where's the fun in that? I did much better this time around, though.