My friend gave me a water bottle that looks just like this. I was really excited about my present.
The other day a ten year old asked me about my bottle. I was proud to show it off. I told her that my bottle has its own filter system. I am able to fill up my bottle with water from anywhere. It is safe to drink because the bottle filters the water as you squeeze it into your mouth. The ten year old went on to ask, "Can you fill it up with water from a toilet bowl?" I wasn't sure how to respond. I couldn't tell if she was kidding with me. I ended up saying something like, "I guess it would depend on whether or not the toilet has been flushed." That really got her laughing.