The reason personal goals can improve your trading ability

Setting personal goals in parallel with you trading goals can have a 1+1=3 type of payoff.

For one, achieving personal goals can give you a boost of confidence and raise your self-esteem. I generally believe that it's impossible to do anything well if you lack confidence. 

Trading is a game of failure and learning to succeed in the face of low accuracy and high expected values can help you develop the mental stamina necessary to survive periods of time where you have no evidence of any trading skill. 

Two, having personal goals keeps your brain in a mode of "figure-out-ability" that is critical for trading success. Your trading tactics and methodology is going to come from much trial and error.

When your brain is conditioned to figure things out, you're in a natural state of "curiosity leads to revelation leads to eventual solution." 

When I have had to come to the trading whiteboard "cold" so to speak, it took me much longer (days and weeks) to get my brain in gear to figure out a solution. 

Lastly, you'll meet new people along the way when you have similar interests. People tend to like and become friends with other people who share experiences.

Maybe some of these people would be interested in learning about your trading process and hiring you to manage the money?