Why does the landlady want billy to sign the guest book

THE ANSWER IS DOWN BELOW

Explanation:

She says it's important to sign the guest book because she wants to look back and remember him later on. Billy thinks she means she will look at it at a later time. What she really means is that there will not be a later on for Billy.

demonstrative is te word i think

whatever is after like is what is being compared they are comparing bumping into you like they are scared to catch germs you have and to you being contagious