Simple enough to double click on something... no sweat. Many apps, programs, features, operating systems, & even some of our movies or their folders require a double click. A click is the easiest thing in the world to do except blinking. Clicking twice is almost as easy.
I'll estimate 1/4 to 1/3 of everything I click on requires a double click no matter what browser or operating system I use. In Linux, & windows in its default settings, almost everything requires a double click. It was considered an anti-goof mechanism so you don't accidentally click on stuff, delete stuff, or change stuff that you didn't want to.
It's handy if you got pets or kids, so they don't click on stuff if they get near your computer, & screw up you machine or send an email to Mars just by bumping something. I have my windows & Linux set for single click rather than the default double click though, but there's still a lot that requires a double click anyway.
I'm lucky that all my pets learned within weeks not to touch keyboards... I got a lot of keyboards. I think screaming as soon as they stepped on one as babies made them figure out early to stay away from them. It's usually pretty quiet around here, & I don't scream often, so it was easy for them to figure out.
Pets are a lot like kids -- if you yell & shout orders at them all the time, it gets confusing to them, so they don't know what to do. Or they think whatever they do will get a yell or orders, so it doesn't matter what they do. I like to keep it short, & simple so they don't get confused about what I mean.
But the cats have caused some accidental clicks. They'll rub their face against my hands while I'm typing or using the mouse, causing a click or miss-type. I also gave up trying to get cats not to step or sit on a remote control or portable radio nearby. I guess I never screamed loud or enough when they stepped on them. I just say "Hey!" & push them off of it. And, although they won't step on a keyboard, if I close the lid on a laptop, they can't wait to step on it or sit on it.
With cats, I don't try to make them learn too much & make it confusing, that way they actually learn more. I live alone. So except for if there's somebody at the door or a phone call, they never hear me speak unless I'm talking to them. With everybody texting, hardly anybody calls anymore... I just get texts & messages most of the time. So when I talk, they perk up & pay attention trying to figure out what I'm saying.