my recent experiences show that things really have changed lately. tools are different, materials are different, and there are NEW safety standards and practices you should follow. Like the whole arc fault thing....never heard of it until a few years ago. Found out recently that OSHA requires you to wear a hard hat when using a nail gun. Presumably someone figure out how to nailgun their skull.... Ways to waterproof doors and windows have drastically changed recently. Chemicals and materials that used to be common, are now considered to be totally dangerous. Like Methylene Chloride paint remover, asbestos insulation, heck even dust from concrete cutting operations will kill you! Fumes from "great stuff" foam insulation are dangerous too! NOBODY sweat solders copper pipes for plumbing anymore...its either sharkbite if you are a duffer, crimp if a pro, or pex pipe. and on and on. So i guess what i am saying...you have to try to keep up on the latest methods and safety procedures. things DO change.