I am routinely surprised by the unprepared people I meet on the trail. I'm probably over-prepared for hiking, with extra water, a small first-aid kit, hiking shoes, and a map of where I'm hiking. But I've made the mistake of being under-prepared for hiking (Grand Canyon, 1997) and I'm not making that mistake again.
To illustrate my point:
On our recent hike from the Airport to Two Harbors on the Trans-Catalina Trail (TCT), Thing 1 and I met up with a couple who had hiked into Little Harbor from Two Harbors. They looked to be about my age and mentioned that they had been visiting the island for years. They were very nice folks, but I had to roll my eyes when I saw that she was shod in flip-flops and he was killing off a big oilcan of Foster's beer.
Realize this: she walked 11 miles in flip-flops that day. Were they really so comfortable after 11 miles? Wouldn't shoes with, say, arch support have felt better? Or perhaps shoes with captured heels? I talked to her on the trail a bit -- she told me that her feet were slipping out of her "shoes" as she was climbing the very steep ridge out of Little Harbor. She was lucky that was all that happened. I've seen some gnarly injuries on the feet of people wearing flip-flops in the field: bloody scrapes, nasty gashes, gruesome toe injuries... Flip-flops: OK for around town, bad for the trail.
I met them as they puzzled over the hiking map posted in the Little Harbor campground. I gathered that they'd started on the TCT from Two Harbors to Little Harbor and got side-tracked onto the road between Two Harbors and Little Harbor. They were wondering how to find the trailhead for the TCT to take it back to Two Harbors. Clearly, they didn't have a map with them. Not a deadly mistake between Two Harbors and Little Harbor, but not a good idea either.
That he thought Foster's beer was appropriate hydration for a 10+ mile hike also blew my mind.
Nice people, but no map and stupid shoes? Doesn't add up to an enjoyable or safe hike to me.