I made the jump from hobbyist to making a living in EE at 40. This followed mechanical engineering and manufacturing careers, among others.
I can now think of an idea, shake it down, design it, engineer the mechanics and electronics together, design and write the software (my first career), and then manufacture it without having to rely on others. Keep in mind, my goal is to 'invent' things and get them to the point of manufacture. I am not really great in any specific engineering discipline to be honest, but there is no real reason I could not focus on something to become an expert if I choose. At 33 years old, you can switch careers a few times if you wanted.
The key, is that you have to be seriously dedicated. Unless you are already wealthy, you have to make a living and get your education at the same time. You also have to build some experience beyond just a degree. As an employer, I am VERY skeptical of fresh graduates. This is from personal experience trying to hire recent grads coming from good schools. The classes will teach theory, math, some ideal circuits, analysis, etc. To be effective in the real world, someone like me would be looking at what you can actually do, not just how well you did on a test.
I could go on and on about how many useless recent grads applied when I was hiring. Very smart and very useless while also expecting to get paid a ton of money because they have a degree. Note to those in engineering school - employers make money from your performance not your degree. be prepared to show that you solve problems and you will be more likely to get hired.
Anyway, back to the topic. Go for it, dive in. Make it happen.