People carry their credentials with them everywhere they go. Sometimes out of necessity for example when trying to establish credibility. Other times, it is not very necessary, it’s just plain old ego trying to manifest itself.
So long as you still carry those credentials and are hard at work at it, then fine. Use it. But be very careful about using them if you aren’t ‘at it’ anymore.
For example, you cannot tell your friends at a party that you are a martial artist just because you earned a black belt in ‘whatever-do’ 20 years ago and have not since kick any higher than your heel. You WERE a martial artist. Thesecredentials need to be updated all the time.
If you wrote a few books years ago, perhaps you can call yourself an author, then. But if you haven’t written anything except emails and is not even working on your next book, are you truly an author?
What are you?