A lot of startup founders, including myself, fall in love with the idea of building technology -- but quickly learn founders are usually required to be great salespeople more than great technologists.

I figured that out from doing photography. People are like "wow you take good pictures you should be a photographer." They never go "wow you love working long hours and doing paperwork, you should start a business!"

Yes. If it's a business (as opposed to, say, a hobby), success lies in being good at the administrative side. Even something that's kinda both like Linux: every interview I've read with Linus T in the last decade or two he makes it very clear he spends virtually all of his time managing administrative tasks.