Hard, yes. I summited at age 65 after about 6 months semi-serious training with lots of cycling for my legs, stepper at the Y and three practice climbs up to Wheeler Peak in NM for altitude training (13,300). g Adventures was my climbing company and I couldn’t recommend them more. Samwell Danford was our leader. We had a group of 11 and all summited, although our 22 year-old from Switzerland was an hour behind us. Perfect blue sky day and temperature +2 C on top. The acclimatization days via Lemosho were instrumental in getting everyone up. I was the only one in our group to experience no altitude sickness save for two minor headaches treated with ibuprofen. All others had various combinations of blurred vision, vomiting, dizziness and abdominal cramps. I was the oldest in the group, so maybe I trained more to compensate. This was my first major hike to altitude. I’m planning Everest Base Camp in March 2019. Longer trek, but a little less altitude - not much, tho - and a lot more crowded. My advice: train, use good gear (try out those boots - I replaced mine as a result of my Wheeler experience) and choose a company with a good track record. You can do it on the cheap, but you’re worth the investment. Skip any company that says it has oxygen tanks. If you really need oxy, you’ve exceeded your limit and knew it. Descent is the only treatment for AMS. Oxygen is for Everest (and not EBC).