Quote from Ghost of Cutten:
I worked solo for years and became less anti-social. You can get your human interaction through social life - put in some effort there and there is no reason you should turn into a hermit. However, I think there are other major disadvantages to working alone, the main one being lack of an external checks on your mistakes, oversights, and deterioration in discipline - 2 minds are better than 1. Also, someone else who is enthusiastic about work, makes you more enthusiastic about work. Anyone working solo is going to be at a huge competitive disadvantage to someone working with a smart, motivated colleague.
So, if you are a very disciplined loner, and happy to chug along earning your keep without ever getting close to realising your full potential, then trading solo may be for you.