We blame bureaucracy for being wasteful and taking too long when things like the Denver International Airport or Boston’s Big Dig arrive years overdue and billions over budget. But it’s not just huge organizations and the government that mess up planning. Everyone does. It’s the “planning fallacy.” We think we can plan, but we can’t.

Studies show it doesn’t matter whether you ask people for their realistic best guess or a hoped-for best case scenario. Either way, they give you the best case scenario. It’s true on a big scale and it’s true on a small scale too.

We just aren’t good at being realistic. We envision everything going exactly as planned. We never factor in unexpected illnesses, hard drive failures, or other Murphy’s Law-type stuff.

If you believe 100% in some big upfront advance plan, you’re just lying to yourself. There’s a good side to this too though: You’re liberated. That messy planning stage that delays things and prevents you from getting real is, in large part, a waste of time. So skip it. If you really want to know how much time/resources a project will take, start doing it.