The first appearance is when you hit your thirties. Just a glimpse, but then you can feel it. May be it is Tommy, your colleague who noticed it first; or your cousin Nicky who had to finish this project in the last minute and comes running to you for help, and leaves with the job done! You are too busy enjoying the adulation to give it a serious thought, but then it makes another appearance, and then a few more. Before you knew it, you are in limelight; known as the EXPERT who is there for people when they needed help.
You may not be in your 30s now. You could be younger, or older. You may have found it, or are in the process of confirming it.
No matter what, you are an expert; a celebrity of sorts in your little world. Busy with your otherwise hectic schedules but refusing to say NO to those little projects from friends. Least because they have no other options. it's because you love doing it. And they keep coming.
People who have expertise just love to share it. That's human nature.
Here is something for you to consider. You could make this world a better place by sharing this gift of yours - your expertise! By teaching someone to get good at the same skill, you are getting them started on the same path of passion that you happened to take someday. Sure enough, there was someone who inspired you that day. It's your chance to be that inspiration today. So go ahead, inspire hundreds and thousands and many more.
By the way, you could potentially earn a living out of doing this. Can life get any better than this?