Reading and not understanding

I can't remember when I first read The Innovator's Dilemma, but it was only a few years back when I first read The Tipping Point. Both are good books and compliment each other. However, some interesting conversations over the long weekend here made it clear to me that some people who say they've read them either haven't or have failed to understand them. Now it's one thing when friends fall into this category, but it's a completely different thing when it's business leaders quoting them as gospel to back up dubious choices. No individual's names and no company names, but it turns out it's quite common in our industry. Probably elsewhere too. Maybe there are some texts (books, papers etc.) where you should be forced to pass a test before being allowed to refer to them.