I don't remember mountain climbing being so hard

Me and my husband climbed Mt. Monadnock in Jaffrey, NH yesterday. I haven't been climbing in years. My family did it every weekend when I was a kid, of corse that was almost 40 years ago. The weather was beautiful and the hike was only 4 miles. I didn't think it would be hard since I am in good psychical shape. The trail was all rock and had a steep incline the whole way. We left the Gatorade and the water in the car because we underestimated the difficulty of the climb. That was a huge mistake. I became dehydrated very early on and had to rest almost every 5 minutes going up. I wore my knee brace and my knee was giving me grief. It took all I had to finish the climb in 4 hours which is average I guess. Got a good workout but boy was everything sore as soon as I got in the car and this morning. Was not going to do anything today but got out for a 9 mile slower than normal walk on the beach. The soreness seems to have gotten better since I stretched them with the walk. I feel accomplished for finishing the hike. There were times that I really did'nt think that I would make it. Thankfully we met a ranger who gave me a Gatorade and a nice couple who gave me a bottle of water and a granola bar. Without them, I don't think I would have made it.