I haven't run a business in a while but when I did I found I was actually more comfortable because the interactions are typically more scriptable and the dynamics are clearer than when you're dealing with peer employees. When you're dealing with customers, you're interfacing on behalf of the business and can adopt a 'business' persona while speaking about things you are expert in. Often you deal with people in bursts and don't need to interact with any given individual too often; with peers it's a lot more vague and confusing, and you're with them basically all the time for years so it's much more exhausting.