Slow iteration speed and pace of learning, I think. If I were going full-time on my side projects I'd make mistakes (and learn from them) much more quickly. As

Slow iteration speed and pace of learning, I think. If I were going full-time on my side projects I'd make mistakes (and learn from them) much more quickly. As it is, any mistake takes a while to be realized and cuts into my momentum and energy significantly, because I get more emotionally attached the longer I stay with a project.