I think there's an ever growing list of things that we wish we would have known then...the "What I wish I knew then that I know now" list. I doubt it ends. And that's okay. We gain a lot of experience from our wish we would have knowns.
One thing that's been nagging at me lately that I wish I would have known is that I wanted to be an author not a doctor. Yup. When I was in school, I said confidently and on multiple occasions that I wanted to be a cardio-pulmonary surgeon. I should have known from the fact that I already had specific words in place that I should be an author. I think most kids say "A doctor" and then figure out what kind after they start school.
It's not like I didn't think I couldn't be an author, either. I knew I had a fair amount of talent writing. It was something I enjoyed. But as a lucrative career, it seemed silly. Maybe that's the other thing I should have known. How much "lucrative" I really needed (turns out, not as much as I thought when I was a teenager).
I'm lucky, though. I figured out that not only did I WANT to be an author, but also that I COULD be an author and went after it. I stopped making excuses and started writing. Then I took a deep breath and uploaded to amazon. Then I took an even bigger breath and hit the publish button. This year, I took the biggest breath of all and hired someone to design the cover for me (Erica Crouch did a FANTASTIC job!).
Maybe that's all there is to it to shrink the "wish I would have known" list. If you really want something, take a deep breath and do it. And if you don't need to take a deep breath before doing something, is it really what you want to do? If it doesn't excite and scare you all at the same time, are you going for what you want or safe? Don't do safe. You won't like it so much. You'll burn out. You'll spend your life wishing you could do, be, something, someone else. That you would have known better. Don't be that person. Be the person you truly want to be.