I just attempted a solo century yesterday. Here are a few mistakes I made (which all the smart people above tell you to avoid)
1.) Came out way,way too strong. By mile 50, I was getting really tired.
2.) Nutrition, or..lack of it. I set out yesterday morning with just a bowl of cereal and a glass of tea in my stomach. I found that by mile 50, I was starting to bonk in the worst way. Luckily, I was able to stop for lunch and get some food/drink in me. It's amazing that the one guy above can do an entire century on no food at all.
3.) Not enough water intake. I think that I only used two small water-bottles worth. Definitely not enough.
I plan on learning from my mistakes; next time will go much more smoothly I hope.