I call this section the "Essentials" as it contains the standardized "essentials" which canyoneering should start from.
If you are looking at this page for a one-time jaunt with your friends, then perhaps you don't need to have every tool and piece of equipment possible in the sport. But if you can see yourself 5 years from now and want to pursue this longer, than yes, you should have all of these things in your possession along with memorizing these knots.
Even coming here for a refresher isn't a bad idea. We can't remember everything forever and so a touch-up is a encourged practice that no-one should frown upon.