Should I not register my nickname in my contacts?
Often overlooked, you can register a "nickname" in the Contacts app. When you replace your email address with your name, use your nickname instead of your first and last name in your contacts. If your first and last name is "Taro Yamada" and your nickname is "Tatamiya", it would be easy to understand if it is a function that displays "Tatamiya" instead of "Taro Yamada".
The advantage of registering a nickname is that it makes it easier to communicate with people you are close to, as nicknames are easier to understand than real names. It can also be used to avoid confusion if there are acquaintances with the same name. Some might say that it feels more familiar than a real name.
You can also register a nickname for yourself in the same way, but it's easier to give commands to the voice assistant "Siri". If you call Siri and say "Call yourself ◯◯", you don't need to add a "nickname" field in the Contacts app.
However, you may want to avoid giving yourself a nickname. From now on, not only will your nickname be used when you are called by Siri, but your nickname will also be displayed in the address section of your emails, making it look a little silly. You can check your nickname by asking Siri, "Who am I?"