What's great about pursuing your calling when older is you know yourself better now. I know I had a hard time figuring out what I really wanted to be when I grew up. That's not to say, floundering for 20 years is the trick. I never did that. But, I certainly went down some paths which were not suited for my brain.
In HS, I wanted to be a Chemical Engineer. So, I took all the prerequisite classes, AP this and AP that. Problem was, I didn't bust ass, so my grades were a notch or two below CE material (back then there were only about a dozen schools where you could even get that degree, so competition was fierce). So, I enrolled as an Electrical Engineering major.
I learned pretty early that EE was not for me. Too much coding and off-the-wall math, not enough hands on, common sense stuff which put my brain into harmony like chemistry did. So, I switched to Mechanical Engineering with emphasis on materials. I even got me a Master's Degree in that. But, then, a weird thing happened...I discovered that I hated focusing on one little thing for years at a time. In other words, the materials engineering job was not for me.
I struggled for a decade. Hopped from one job to the next, maybe ten jobs in 15 years. And, then--voila! I fell into a technical management job. Suddenly I enjoyed working again. Something about keeping my eye on many balls at a time sang in my brain. Of course, it then took me another 15 years--and, maybe 5 jobs--to find the right management job. I think I finally found it, two months ago