I'm in my early twenties and working. The thing is, I have always liked to follow scientific developments in various fields. Recently I have realized that I should really get a firmer ground in science and math for intellectual purposes.
Prior to this, I was never great in either. I was decent up to the third year of my high school, then the time came to choose a "stream" of study, so I chose arts over science because I was lazy at the time, preferring to play basketball and videogames all day. During math class I would often draw pictures all over my textbook. Up to now, my highest achievement in math has been passing a calculus course in college, motivated by the fact that I had to pass it or else.
Now, I realize I am never going to be a scientist or engineer, as it would take a long time and I already have a decent job. However I would still like a better grounding in science and math. I can't take a master's degree in it because my first degree was a business degree. Any suggestions on how I should improve myself? Currently I'm reading up a calculus book on my own and doing practice exercises.