I think you can tell how stressful your life is by how often you have to buy toothbrushes.
If you think your life is stressful and you buy less than one every 3 months, you should reconsider; you may have job stress or family turmoil, but you are not lacking basic life foundations. For example, in my jobless, homeless graduate life, I am buying on average one a week - at best one every two weeks. I am constantly misplacing them - leaving them at different houses, in different countries, on different sinks.
I await the day that I can wake up and know my toothbrush and paste (without excess gumming up the lid) is in a twee little pot in my bathroom.