I had a really interesting conversation with an entrepreneur recently. He is the brother of a close friend who wanted to talk about his world-changing start-up idea. It was so world changing, in fact, that he didn’t want to tell me about it until I signed an NDA. I gave him my usual spiel about why operating in "stealth mode" is a terrible idea. (Your idea probably isn't that new, and if you don't get some feedback, you will probably fail due to your incompetence.)

He’s a lawyer by trade, so he was more argumentative than most and forced me to defend my opinion about why he should be sharing his ideas freely instead of requiring NDAs. As we talked, he began challenging other start-up philosophies I hold dear. I told him he should launch fast; he said he wanted to take his time and make sure he got it right. I told him to forget about scaling until product-market fit had been validated; he knew it was the right product and wanted to scale from the beginning.

"What is the basis by which you are forming your opinions?" I eventually asked him. "You have very strong opinions even though you’ve never done a start-up before."
"I’m using my common sense," he replied. "I think through each problem and come up with a solution that makes the most sense to me."
I asked, "What if I could prove to you that your start-up common sense was categorically wrong?"
Finally, for the first time in 45 minutes, there was silence on the phone.

There is something about how to launch a start-up in 2013 that is the exact opposite of what an intelligent, thoughtful outside observer will intuitively do using his or her own common sense. But for me to prove to my friend's brother that his common sense in this particular subject was categorically wrong would mean that he couldn’t trust his own judgment. Therefore, his most relied upon tool would be of no use to him. It’s a terrifying thought.

I know this terror well. After I finished my MBA, I had developed my own common sense about how to launch start-ups. I launched a company relying on these beliefs, and it failed miserably. One of the things my first trip through Y Combinator did was rip apart my common sense. It was really tough.

Do you need help with your start-up common sense? Here are my suggestions for retraining your brain:

1. Launch your product and talk to customers. Jumping in and launching a product or service is the single best educator. Yes, it's scary, and very often entrepreneurs will choose to do absolutely everything possible to avoid launch. But launching a product as early as possible--even so early that you are thoroughly embarrassed by its quality--helps you start learning what your customers really want much, much earlier.

2. Read up. You not only need to read a few books, you need to make sure you read the right ones. I have six specific books that I recommend every entrepreneur read before he or she gets too deep into launching a start-up: Lucky Or Smart? by Bo Peabody, Getting Real by the guys from 37 signals, The Art of the Start by Guy Kawasaki, The Four Steps to the Epiphany by Steve Blank, Rework also by the guys from 37 signals, and Founders at Work by Jessica Livingston. These books are not only helpful, but they are paradigm shifting. Plus, you can read them quickly and know that you are on the right path. Also helpful: the daily curated articles on Hacker News.

3. Get into an accelerator. Whether it’s Y Combinator or 500 Startups or Tech Stars, accelerators are one of the best ways to get your start-up off on the right foot. Not only will you benefit from the advice, you’ll also feel the pressure of keeping up with your peers.

4. Find a great advisor. The very best advisor you could have is someone who has successfully done what you are trying to do and is only 18 months ahead of you. Not some industry superstar. Not a famously successful entrepreneur. Not an investor. The best pure advisor is a fellow entrepreneur who is just a little bit farther down the road, because this person has only recently gone through the epiphanies that you are currently in search of.

5. Stop taking bad advice. In my opinion, the worst kind of advice is outdated advice. Successful people and big company people are especially prone to outdated advice. What worked at a big company in 1998 probably isn't relevant to your two-person startup in 2013.

The first step to recovery is admitting you have a problem. As a confident, stubborn guy who thinks he’s always right, I can attest that it isn't easy. My advisors ripped apart many of my strongest held beliefs. And I can’t thank them enough.