Brushing teeth is a good habit. An easy-to-build one, I’d say, thanks to the immediate reward given by the refreshing sensation. After brushing, you feel clean right away.
On the other hand, flossing teeth isn’t a habit as easy to build. After flossing, what comes to mind is how dirty your teeth still were even though you just brushed, not how cleaner they became. There’s no such thing as a fresh sensation in your mouth.
When you finish brushing your teeth, they’re still dirty – no doubt. However, it’s still gratifying, since you’re fooled by the menthol ability to trigger the cooling sensation. (Hence the human inclination to brushing rather than flossing!?)
In terms of dental health, though, flossing teeth is more effective on cleaning than brushing1, even if it doesn’t feel like it. There’s no immediate reward in flossing, but definitely a long-term one.
What am I trying to say? Apart from dental health advice, that sort of reminds me that we shouldn’t rely on feeling instantaneously compensated as a fuel to build habits. After all, some things just need the long-term to pay off; for we to benefit from them.
I’ve read that at some point in my life but don’t remember where. You can find some resources out there, such as “What’s More Important: Flossing or Brushing?”. Anyway, I think we’re safe assuming that flossing is, at least, as important as brushing.