I definitely used to be more so than now, but I'm still extremely private about it. Historically, people with a tickling fetish have been some of the more cautious and private people, as compared to many other kinks. That's just generalizing, but that's overwhelmingly been my experience in chatting with many over the years. It's not quite clear why that is, but I find it a fascinating observation. When I was a teenager, I would have felt completely destroyed by one of them finding out. That has slowly changed to feeling like it would be more of a very uncomfortable inconvenience. I think it has helped being married to a Ticklephile and being able to share those feelings and anxieties with her while building confidence and strength together.
Again, we both still feel very shy about it, but less so than before. But, I feel that even if we weren't that shy about it, keeping such a secret from most people in our lives would still feel fun and exciting.