How should I think about running a company?

Companies sound serious.  When you start thinking of yourself as a company, you start acting like one. Worst of all, you won’t work on slightly crazy ideas. When you have a company, the clock is ticking and people expect results. It’s far better to be thought of—and to think of yourself—as a project than a company for as long as possible.

Sam Altman in Projects and Companies
How should I think about running a company?

What are some pitfalls of companies that ultimately fail?

The main problem is that companies stop doing what they were doing during YC—instead of relentlessly focusing on building a great product and growing, they focus on everything else.  In general, startups get distracted by fake work.  Two particularly bad cases are raising money and getting personal press. But the list of fake work is long.

Sam Altman in The Post-YC Slump
What are some pitfalls of companies that ultimately fail?