Opening the book…
This sounds backwards until you've felt it. A dull chisel or plane needs force to cut, and force is where control goes to die: you lean into it, it skips off the wood, and now the edge is heading for your hand with your whole weight behind it. A sharp tool cuts where you aim it with a light push, so it stays predictable. Dull tools don't just work badly, they hurt people. Keep them keen and they obey.
Learn to sharpen and do it often, before a tool feels dull rather than after it's fighting you. A quick touch-up on a fine stone or a strop takes a minute and keeps an edge singing through the work. Test the sharpness by paring end grain or shaving a thumbnail, and hone the moment cuts get ragged or the tool wants extra muscle. Keep your sharpening kit set up and within reach so a touch-up is never a chore you talk yourself out of.
Sharp doesn't cancel the other safety habits; a keen blade still cuts you if you put a hand in its path or push toward your body. And for demolition, prying, or scraping paint, use a beater tool you don't mind abusing rather than dulling and chipping your good edges on nails and grit.