Do not let SIX YEARS go by without cleaning your bike. Yeah, yeah, you wiped down the frame when it needed it, but the crud that came off the cassette, back derailleur, and crank set last night and this morning was astonishing. Frightful. Unbelievable, even! Good thing you took a picture of the crud; please post it where you can see it regularly. If your bike hates you, it has good reason to do so!

Don't overlube; see "crud" above.

Do not put the bike on the bike rack and then put the packed panniers on it, especially if you have put the bike on the rack so that the south end is to the left. Your left arm cannot support the back end of the bike even when it doesn't have panniers on it; what made you think you'd be able to lift the bike off the rack once you got to the trail?! Oh, wait.... you didn't think. Never mind! (Please do remember, however, for next time!)

A ride that begins with getting the handlebars tangled in your hair as you struggle to get the bike off the rack (see previous paragraph) is not off to a good start.

When riding the C&O Canal towpath, watch for the closest mile marker as soon as you get on it instead of looking at the canal as you ride to see what birds, insects, mammals, etc. are in it. Look at the scenery AFTER you know exactly which mile marker is closest to where you left the car.

Swains Lock is at mile 16.6 on the towpath, not "just below mile marker 20," as you thought because mile marker 20 was the first mile marker you noticed. There's a good reason why it seemed longer than a mile from the car to mile marker 20!

If you want to get in a 50-mile ride, it helps to know exactly where you started the ride; if you don't pay attention to where you started the ride, you might end up with a longer ride than you intended. You will not be happy about that; you will be in pain. The sun might set, too, before you find your car, and your best friend might not be where she can look online when you call her from the trail to find out whether the place you left your car is still in front of you.

Get a light on your bike; see previous paragraph.

Deciding to do 50 miles, further than you've ever biked, on the same ride you are riding with packed panniers for the first time, to see how it feels to have the additional weight on the bike, was not a good idea.

Vultures know. Yes, they know, and those black vultures really WERE waiting for you to keel over.

Put aspirin, Aleve, ibuprofen, and Tylenol in your handlebar bag; you need them handy-by.

Buy a new saddle.