No worries, the only type of Alstimers that is hereditary is a type of dementia that starts affecting you in the early 30s but if you had that your grandmother would have shown sign in her early 30s as well. according to research. However, my great grandma and grandma both have the same kind and my mom is showing signs but she also has cancer so it could be from that.
You pull it off to make it easier to light. :) My fiancée told me about that when we first started dating. I remove all of mine now. Just be careful, it makes them not so child proof anymore when you take it off.