Not a game deeveloper but was really interested in the field when I played Antichamber and learned about the developer's story. Imo it depends on what your criteria for 'good' is but it's really hard in general. Imo 'without going to University' isn't that big an issue since there are so many resources online. But being a one-person developer comes with many restrictions especially with art and music, as you'll need to be creative with them to fit your budget/abilities. If you want to make a popular & groundbreaking game that receives critical acclamation, you'll need some original & interesting idea/mechanics, which is quite hard given how many indie games there are these days and it feel like every idea you thought of has already been thought of by someone else. And you'll need a lot of determination and courage to put your work out there to keep iterating on it. Then you'll need to advertise or nobody will notice it. Might be a bit easier if you just want to make a good game that is well-polished but nothing too 'special'. But it will still be a loooot of hard work. Don't be discouraged though, just realize the hardship you might face.