It's almost guaranteed that if I'm carrying it that day, I won't need it. It's only when I forget it at home that I really need it. That's why I carry so much stuff, it's just to ward off the bad luck. It's worked so far with that lottery ticket in my wallet, ever since I've carried one, I've never needed it. smile

I tend to carry the same stuff no matter where I hike. During a longer hike, I carry it because there's a good chance I'll need it. On short day hikes, I'm not too concerned about the weight anyway, and I just carry it for excercise. I figure instead of carrying extra weight to work out, I might as well carry something useful, at least that's what I tell myself. The truth is I'm just lazy, I leave my backpack fully packed so I can just grab it whenever I feel like hiking, so it's too much trouble to unpack and repack.

Funny you guys mention Half Dome. Last time I was there I also watched the rescue helicopters going up to retrieve a hiker who had fallen off the cables. Luckily our group was already done and watching from the comfort of camp. But you do see a lot of people that are just unprepared for the hike, even during good weather. Too many of them start out the hike in just t-shirts and shorts and a water bottle. The last time we went my friend had to give the rest of her water to an older couple who had run out of water as it was getting dark, and were not even half way back down. And the first time my gf went there, their group had to guide down another group of about 8-10 people who never even thought to bring one flashlight between all of them. I can only imagine if something unexpected like a summer storm were to happen, you'd probably have one the largest mass rescues of all time.