Rod Johnson, creator of Spring, programmer that became entrepreneur:

One thing I think that you really need to be careful of as well, particularly if you, like me, are a programmer, is don’t get carried away writing code. Typically in my experience anyone who is a good programmer is pretty passionate about it, love writing code, get addicted to the process of writing code, fell pretty good about their code basis. As soon as you get down that path you are not thinking straight anymore and now you are increasing your emotional investment, you are having lots of fun writing interesting code and you are no longer in a place mentally where you are going to be trying to find some reason that you shouldn’t write that code. That has been a big lesson for me that the quicker I get to coding, the longer it takes me to ask the kind of questions I should ask upfront.

Linus Torvalds, creator of Linux, programmer that still programs:

I’m interested in programming. When business started happening, I didn’t get into this for the business side. I wanted to do programming. When other people started selling Linux, I said “Yes! Now I can avoid caring about that side too.”

I never had to deal with single business related thing in Linux ever. Seriously, I had to deal with lot of other things but business related things… I got queries and I just said “I don’t care.”