I Wish I Knew Then What I Know Now

Since this is Beginner Triathlete and many on the forum have some years in triathlon, I thought as I was out on my bike tonight some things I know now I wish I knew starting out.  So lets hear them!   I'll throw in a few that I experienced on my ride tonight.

• If your chain drops to the outside of the big ring, immediately shift to the small ring and keep pedaling, the chain 9.9 times out of ten will get back on.  If it drops to the inside of the small ring, shift to the big ring and keep pedaling.
• Arm Warmers - on evenings that cool down, nothing beats having some arm warmers in the jersey pocket.
• Chip seal, rough country roads - If you are not racing or trying to hang on the back of a pace line, let some air out of the tires.  85 psi gives me a smoooooth ride.  Just use HR, Power, etc and don't worry about the mph.  It can make training rides a lot more enjoyable.
• Mirrors - I know, I know, but..... I have found without fail that if I'm out riding on a single lane road, if I take the center of the lane but watch for approaching traffic and then move to the right fog line as they approach, the motorist gives me all the room in the world.  I've never been buzzed using this approach.  I think it is the simple act of showing you are trying to get out of their way that makes them return the favor.  No break of pace, no problem.

Like I said, these just came to mind as I was cycling along.  Let's hear em gang.  Swimming, cycling, running.......

Oh....please, please, please don't get into debates on this thread.  Just throw out what you would offer new people and let them pick what they want to try.