Seth Godin, a marketing guru, passes along this nugget:
One mistake marketers make is a little like the goldfish that never notices the water in his tank. Our environment is changing. Always. Incrementally. Too slowly to notice, sometimes. But it changes. What we care about and talk about and react to changes every day. Starbucks couldn’t have launched in 1970. We weren’t ready.
Of course, sometimes the reason that our perspective on an issue changes is because the thing itself has changed, perhaps imperceptibly. In other cases, it’s because our perceptive apparatus has been modified in some way.