When I moved into my dorm at college I thought I was a God. I had gotten into a good college and I had tested out of the freshmen calculus and physics classes. I got to start math a year ahead of my peers and take differential equations and physics 2 as a freshman. Going in, I felt extremely confident in my decisions.
A few weeks into the semester I was failing. It blindsided me. Admittedly I wasn't the greatest student in high school, but I had always had an excuse for poor grades back then. I would just say that I had been too busy to study, I didn't care, or I was unmotivated. My ego was inflated by good test scores in high school. I honestly thought I was smarter than everyone else. Boy was I in for a rude awakening in college. I felt so dumb after those first few weeks.
Luckily for me my neighbor was an extremely bright and helpful student. R.R. was a very advanced student, taking graduate level math classes as a sophomore. Where I tested out of calculus he tested out of pretty much every math class the college offered. On top of being a math genius, he was good-looking, engaging, friendly, and apparently had absolutely no faults.
I suffered through a half a semester of differential equations before I swallowed my pride and went to R.R. for help. He needed a night with my textbook to review the material as I assume he hadn't looked at it since he was eight, and agreed to help me. He coached me through the rest of the semester. With his help I ended up getting a B+ and avoided failing. Most importantly I learned important lessons of studying from him. The more I learned from him, the more I realized that his skills came from hard work and studying. By tutoring me he showed me his tools and tricks and got me started on creating my own. I look up to him for putting in the work and reminding the rest of us that you determine your success.
It's easy to fall into the trap of thinking that 'being smart' is what determines our performance in school. I won't deny that natural aptitude plays a factor but so many people think that it is the only factor. It seems like the easiest possible explanation because it doesn't require any extra work and is a compelling excuse when we fail. You yourself are facing this tension without recognizing it. You blame or thank your intelligence often. How often have you either claimed you failed because you just don't "get" something or aren't smart enough? Or on the flip side, that you passed because you are a "good test taker"?
Early on, you built certain tools to rapidly acquire and process new information and you've relied on those for years instead of developing new tools. You never learned what to do when those failed. I had to sit back down and really learn how to study before I could truly have success.
The college I went to has a 97% graduation rate. The vast majority of people who get in make it through. As for the 3% who fail, they burn out quickly. It's typically a first year student who has never learned how to study and refuses to ask for help. There are plenty of students who come in and are over their head like I was, but the difference is that they begin to seek out the tools to be successful. They acknowledge their inadequacies. They don't blame their lack of intelligence, they blame their lack of motivation. I found someone to help me and now I'm hoping to help others as well. When I was a senior I saw freshmen struggle and I would sit down with them to guide them. By the time I graduated from college, I had become some freshman's R.R.
You don't ever need to worry about being smart enough. You always have an opportunity to make yourself "smarter" because being smart means that you have put so much effort into your studies that you make it look effortless now. You are the one who decides if you burn out or have success. It's scary to acknowledge that it's your own decision but it's also empowering because it means there is something you can do about it.
So go on out and do it.