At the hike on Saturday, I learned my gear wasn't really up to par. For example, proper hiking footwear should be boots with ankle support and remaining tread. Evidently my waterproof shoes with the treads worn out were a safety hazard.
Secondly, a good hiker should be prepared for the elements, especially when hiking in the Colorado mountains. A storm could come up unexpectedly, or the weather could change, and you need to be prepared. Proper gear includes at least 2 liters of water for hikes of our distance, long waterproof pants (not shorts), a rain jacket or poncho, gloves, a spare hat, sunscreen, bugspray, proper food like almonds or apples or protein bars, and of course a map of the trails should you get seperated from the group. (But you should never get seperated from the group by a distance of longer than 20 yards. What if you got hurt and no one knew?) So again, my child's sized backpack - it was small, and I liked that I couldn't pack more than a camera and a granola bar practically - that could only hold one liter of water wasn't sufficient.
Lastly, good socks are a hiker's best friend. Cotton socks, as I have learned, absorb moisture and don't wick it away. Wet socks constantly rubbing on bare skin for 6 miles = blisters. So what's a girl to do? Wear wool or synthetic wool-type socks that are cushony and wick away moisture keeping your feet dry and comfortable.
So thank you, REI, for teaching me that even a simple athletic endeavor like walking can be an expensive hobby! But, when investing in your health you really can't go wrong.