Here's our friend Manutius with his pal Jean Grolier, a French book collector, having a chat. Maybe they were talking about how an interest in books and reading makes one ignore what must have been a glorious view of the Grand Canal right behind them.
We all are dedicated and sentimental about our paperbacks because they are the perfect portable distraction. And we don't have to share them like a text message or an email and no one will respond, than God. Reading is a solo pursuit; by reading we travel lightly to other worlds.
And they are versatile. We can take them to the beach (and ignore that view too. I am sure Manutius would be proud),
Or drop them into the tub (in Manutius's time and place that would have been "drop them in a canal"),
Or do other things and read.
Which means, of course, that if you are reading and doing some other activity, you won't abide this warning sign because you simply won't see it. Will the book police come and rip that paperback out of your hand? Not likely. So just keep reading.
p.s. Same rule applies to eReaders and if you want to read Fall Creek and don't have one, look here, although it might be hard to stuff your desktop computer into your pocket, let alone take it on a bike.