Hate it more when I don't act on it. 2nd grade (about 1972), we made pinwheels in class. I said, "hey, you could make a small one of these out of razor blades and put it inside a vacuum hose. Then, you could suck up your hair and cut it all to the same length. "Don't be silly, Thomas." 10 or 15 years later... flobee.
And, a while back, I thought about making a caffeinated soap. "Get your caffeine *before* your morning cup of coffee!" Decided that I'd be too exposed to lawsuits after some idiot bathed their 2 year old for 5 hours with the stuff. A couple years later, some idiot actually is marketing the stuff. (wonder if he's been sued yet?)