The thing about triathlons...

"Why suck at just one sport when you can suck at three?"
That's the thing...it's three sports.

When I'm in the water I'm a swimmer.
When I'm riding I'm a cyclist.
When I'm running I'm a runner.
When I cross the finish I'm a triathlete!

For the swim you get to stand around until it's your turn to start. Until then you might get a chance to warm up and stretch but for the most part you're standing around in a crowd of people waiting. As you enter the water and start swimming you become part of a sea of flailing arms and legs.
When you're done with the swim you run straight to the bike. Running barefoot sucks. There's no warm up or stretching for the bike...the swim was your warm up. You quickly try to dry off enough to put on your cycling socks (if you wear them) and cycling shoes. You also try to slow down enough to take on some calories and fluids. You grab your bike and run with it to the 'mounting line'. Running in cycling shoes sucks. Then you're off on the bike. While you're on the bike you have the opportunity to drink and eat as needed. Yum, yum...energy gel packets.
When you finish with the bike you dismount and once again run in cycling shoes with your bike back to the bike racks. Running in cycling shoes sucks. You change into your running gear. You also try to slow down enough to take on some calories and fluids. Now you have to start running after pushing yourself on a bike. The muscles go through some difficult adjustments, both painful and uncomfortable. Now you're running. You have to decide just how much you have to push yourself to make the time you need. You also have to hope you have enough left in the tank to finish. You grab what you can at each aid station as you run by. Again, you have to decide just what you need to keep the engine running. Eventually you see the finish. No matter who you are or how fast you are or what place you're in you have a crowd of people cheering you on. If you're really lucky you will hear your name being announced as you cross the finish line. If you're lucky enough not to throw up you make your way over to the food tent and try to muster enough energy to stuff your face.

"So you ran a marathon, how cute...maybe when you grow up your mommy will let your run a triathlon!"