Chinese toothbrushes

I bought a Chinese made toothbrush in Birao, Central African Republic, near the border with Sudan, and the second time I used it, it snapped.

Was I brushing too vigorously?  I always wondered why toothbrushes were so expensive.  Is it the thisles?

I used to like to make myself bleed, preferring the "hard".  I was told these were bad for my teeth and that I should go with "medium."

When telling this story, someone told me about riding off from the store with a Chinese made bike, and breaking off the pedal on the second downturn.  Funny thing, the same thing happened to me, but I hadn't put two and two together. I always knew I did pedal too vigorously.