I did my first half marathon in Florida some years ago. It was a disaster. I didn't have any records on the race so I got relegated to group "I" (on alphabetical order that's about the last group) so I ended up with a bunch of ladies in wigs and men with iPods not to mention the most delayed corral to open. For some reason the organizers thought it was a good idea to put you on a bridge just after 'kick-off' which is fine except for the part where you have to run with two thousand people in a space no wider than the equivalent of three car's width. Sure enough I lost a shoe which almost fell to the river. Just imagine looking for a shoe, at 5:30 am, with thousands of people running the other way. The good part is I had easy-laces so putting the thing back on was relatively quickly.
By the time I hit the first aid station it was already 5k which is no biggie nowadays but back then I used to start taking fluids one and a half miles earlier. My favourite episode was hitting mile 7 or 8 and a crazy bastard was so pissed off at the crowd he jump at me as to hit me. It shocked me as I lost my breath and almost passed out. Then there was the heat. I trained on threadmills during those days due to the speed I needed to do and Florida's humidity just killed me.
About two miles from the finish line I was in so much pain from the heat and the speed I was doing I cried all the way till the end. As I got to the finish line the dude who actually won the full marathon came in at the same time (remember I was doing the half) so I ended up in the newspapers crossing the finish line about half a meter behind the full race winner.