What I Learned (3): Running

I was running the other day and I was thinking about how many things I didn't know when I started running. Through much trial and error (mostly error), you end up figuring out what works for you, food wise, water wise, shoe wise and more! Obviously, I didn't have a pen and paper with me, and my brain is very similar to Swiss cheese. Therefore, once I sat down to make the list after getting home, it was much, much smaller than I had planned. However, here are the few things that did stick. So, here are a few things I have learned about running in the past several years.
It's okay to walk.
This took me a while to learn. It seems like it's a bit backwards, because usually you walk before you run, but I didn't. If I had to walk, I considered myself done. This was keeping me from running farther. If I would have just stopped to walk and recover, I could have kept going. However, since I started trail running and the hills were brutal, I realized that by walking up the hills, I can save more energy for later! The same goes for any run whether it's on the trails or the roads.
You are faster than you think. 
For a long time, I stayed at about a 10 minute per mile pace because it was comfortable and I didn't really (a) want to push myself and (b) think I could go much faster. However, I decided to try speed training (intervals) after a friend told me how hard but rewarding it was, and by doing that I realized that I was selling myself short. I was a lot faster than I gave myself credit for.
Sometimes you need a buddy. 
I am usually a solo runner. However, sometimes I run with my Dad or my friend K, and it's fun. The time goes by a lot faster, you talk the entire time and it puts the fun back in running. It makes it more of a social session with exercise, instead of a chore.

My running buddies

A bad pair of undies can be your worst enemy. 
I think this is self explanatory. However, as I have mentioned before, some people chose to go without. I am not one of them, but I do believe in the benefits of a good snug pair of undies (but not TOO snug!).
Always carry water. 
I have done the bad thing and assumed that there would be drinking fountains on the trail, or that I was "only going a few miles" so I wouldn't need a drink or that it was not as hot as it really was. Let me tell you, I believe that it is well worth it to carry water, even if you don't end up using it.
It's okay to take a rest day. 
Okay, maybe I am lying about this one, as I still have a hard time taking a day off. I do know though that I feel better, am less sore and am more ready to go the next time when I have a day of rest. It's just hard ON that day to get over the fact that I am "sitting around".
Do you call them undies, underwear, panties, knickers (or...)? What have you learned about running? Do you exercise with a buddy or solo?