Shortly after your friends get over addressing you as "Doctor <lastname>" (this is mostly ironic and will probably only last a day or two) you will find out that you do not actually get any additional respect for having a PhD. Most of the people you know already have one. When say you're a doctor, real people think this means medical doctor, which can result in uncomfortable questions. You'll even start to feel guilty when you select the prefix "Dr." from the drop-down menu when filling out your address online, beginning to suspect that this indulgence is not intended for doctors of philosophy, whatever that even means. People can sense this self-doubt like dogs can smell fear, which reduces their esteem for you further. However, in a pinch, there is a universal symbol of scholarship and stature available: the Lab Coat. It is easy to use. Simply by wearing it, you will be perceived as having the dignity of a medical doctor, scientist (the kind with test tubes), or dentist. This means instant respect. So: Go forth! Stand tall! You're a doctor!