Twenty-seven people can fit into a trail shelter built for 12, sometimes you find Little Debbies tacked to a wall and they restore your faith in humanity, there are 165,000 blazes along the 2,178-mile Appalachian Trail .

The things you learn when you think you’re going to buy socks and you stumble onto a seminar.

Last night, I went into the Cary REI looking for socks. Instead, I found REI associate Katie Ackerman holding forth on her 2009 thru-hike of the Appalachian Trail. In addition to those Little Debbies tacked up in an AT shelter, the miserably rainy night when 27 hikers happily crammed into a 12-person shelter and those 165,000 blazes (which I’m assuming — hoping — she didn’t personally count), Katie shared with a packed house of about 25 these AT insights:

• It cost her about $2 a day to live during her six months on the AT, which began on March 23, 2009, in Springer Mountain, Ga., and ended Oct. 16 on Mt. Katahdin in Maine.
• She didn’t think it possible to hike the trail with much more than 60 pounds on your back, then she met the appropriately-named Kitchen Sink, who had an 80-pound pack. Conversely, she thought hiking with a 15-pound pack was crazy — until she met a guy with a 14-pound pack. (Being small herself, Katie says she gravitates toward the ultralight camp.)
• The notion that, “You can hike happy or you can camp happy” is a myth. You can do both, she says. Just pay close attention to the weight of everything that goes into your pack.
• The best place to shave weight in your pack is with your “sleep system” — your sleeping pad, bag, liner, etc. One caveat: “It doesn’t do any good if your sleep system weighs one and a half pounds if you can’t sleep.”
• There is no right or wrong way to hike the AT. “The phrase you hear over and over is HYOH, or ‘Hike Your Own Hike’.”
• A favorite thing to do when you reach Damascus, Va., isn’t to eat a pint of Chunky Monkey and take a long nap but rather rent a bike and ride the 35-mile Virginia Creeper Trail.
• It takes, on average, 5 million footsteps to walk the entire trail, and the cumulative elevation gain is the equivalent to climbing 29,029-foot Mount Everest 14 times. (That’s 406,406 feet of climbing, if you don’t have a calculator handy.)

That’s the kind of insight/direction/inspiration you can get just about every Thursday evening at 7 p.m. at the Cary REI. In fact, all of REI’s seven stores in North Carolina hold hour-long seminars just about every week. They’re free and cover a range of topics, from thru-hiking the AT to climbing Mount Washington in winter to how to use the GPS you got for Christmas.

Below is a list of clinics currently on tap. Click on the city name for more information on the store, including directions, and to keep tabs on upcoming clinics.

Asheville

Tonight, 7 p.m. Bike Maintenance 201 (for graduates of BM 101).
Saturday, 10:30 a.m. Class: Map and Compass 101
Feb. 24, 7 p.m. Class: Map and Compass 101

Cary

Feb. 24, 7 p.m. Geocaching Basics.

Charlotte

Saturday, 2 p.m. Camping Basics
March 2, 7 p.m.  Appalachian Trail Thru Hike Clinic.
March 27, 10 a.m. Digital Photography Boot Camp

Durham

Tonight, 7 p.m. Appalachian Trail Hiking Class. (If you missed Katie Ackerman’s Cary performance, catch her tonight in Durham.)
Feb. 25, 7 p.m. Geocaching Basics.

Greensboro

March 13, 11 a.m. Bike Maintenance Basics
March 18, 6:30 p.m. Bike Maintenance Basics (Women Only)

Pineville

Feb. 23, 7 p.m. Map & Compass Basics

Raleigh

Feb. 23, 7 p.m. Geocaching 101