Unless it's work related, do not share your real name, workplace, social media accounts, or personal and work email addresses. All of these are pieces of information that can be used to identify you and make it easier for someone to discover information your home address or names of family members.
You may think that you have nothing to hide, but there are some things that you may want to keep private. Maybe you don't want the world to know that you're a hockey player taking piano lessons. Or about any of your other hobbies -- like what you’re playing on Steam, knitting on Ravelry, or posting on that FishOwners forum.
While you might be ProfessionalUsername and talk about your science on Twitter, you could easily be Stanly Fleur on the FishOwners forum. Multiple, unique usernames can help make this happen. If you need help coming up with a new username, there's a variety of name generators out there on the internet.
To keep track of these unique usernames (and passwords), you could use a notebook that's stored in a secure location. A password manager like Apple Keychain, Abine Blur, or Last Pass can also keep track of these for you.