Because bacteria could get on our hands through out eyes, ears, mouth, or nose (since all of which is noted to be connected to one another) and it could make you extremely sick. Although some bacteria is good for you, an extreme amount can make you extremely sick. For example, you can contract ecoli and if that's not treated it can be fatal because you lose a ton of fluid and nutrients! Good luck, rockstar. I hope this is what you were looking for, and you pass! (:
