I think the myth of being "too old" is a stereotype threat like others that tend to push people out of mathematics at various stages, at least in my experience in the USA. But it's not just about mathematical abilities, it's also about how you communicate, write or socialize; that affects whether you learn from others, whether they recognize your contributions to mathematical thought, and so on. Embarrassment and egos can get in the way of people who should be studying together and learning from each other. If you're studying math in college now, I hope you will reach out to some of your younger classmates and work with them.
A couple more words of encouragement. Sharpening and focusing one's mathematical thinking, as well as learning mathematical content, often feel like slow processes (or come in spurts), and repetition may be required; however the progress one makes in a year can look impossibly far before one makes it. I think that contributes to feelings of inferiority that people so often have when it comes to math. You should do more math in college, if you want to. But if you're keeping your job and have a real life and yet have room for math, you're in a great position, and the main obstacle might be figuring out how to contribute to the community. We don't just need published papers on new work; we also need time-saving sources, such as masters' theses, that clarify, organize, and modernize old work. Either way the trick would be getting math into circulation when you're not affiliated with a university. Contact with professors would help.
