There was one time my wife's iPhone would not turn off the light. It kept shining even if you turn on and off the flashlight feature. Told her to turn it off and on again.. She couldn't. I had to watch a YouTube video and do it for her.

I mentioned this to a colleague and he too had to turn it off one day but didn't know how.

The steps aren't intuitive and if you ask me again to do it, I would need to Google it again

Really it's not how often you need to do it, but the fact the most basic and fundamental step of turning off a device can't be accomplished with searching online.