I'm a software engineer, and when I started talking to potential customers about software I'd built, I realized I was much less comfortable with sales than development. I wanted a way to practice sales conversations before having them with real prospects, but I couldn't find anything that felt quite right for what I needed. So I ended up building a simulator for myself. What surprised me wasn't whether I could close a deal—it was how many weaknesses I found in my own approach. I would jump...