THE PATH ITSELF.
Alchemy has been practiced for centuries and centuries. This practice takes a lifetime to learn, and a life time to master, because of it's knowledge, you must combine science with magick, you must know the difference between what is real and fake. This path isn't mastered by everyone who tries to follow it, some people quit because the path takes forever to learn, they are called the alchemy drop outs.
Alchemy takes faith and plus knowledge, what you know is that it turns silver to gold and other things, but alchemy is more powerful then that. Alchemy is more mysterious then that. Doing alchemy in assumption that you can be rich is wrong... Alchemy isn't for making you rich it's for making change. Understanding alchemy is a strong role which some people who study it don't understand. You think that you can turn even rock to gold, well you're wrong, because there is a cycle which it works, this cycle keeps alchemy in check, and keeps your minds flowing.
WHY ALCHEMY TAKES A LIFETIME TO MASTER.
Alchemy is a tough path to follow, because there are many books and many things to learn, it masters both magick and science, you must have years of experience in science and also years in magick to successfully use alchemy in every day work. Learning this path isn't as easy as some people make it seem. Alchemy is dedication, alchemy is one of the hardest paths to follow, and almost 50% of those who follow this path pass while the other 50% drop out of alchemy because of the long rate.