Look up Follow Bigfoot on YouTube. He did his Thru hike in 100 days last year and has a lot of post hike videos talking about strategy, planning, etc. Can it be done? Sure! The biggest observation I have is people who have never hiked on the southern or northern portions don't/can't grasp the difficulty of it. It's not impossible but knocking out 25-30 miles a day requires experience, conditioning, and a very dialed in kit.