When I was the youngest guy in the room, I didn't want to admit when I screwed up.  In my mind, I must have thought by admitting my mistakes, I was at risk for exposing myself for what I (obviously) was --   the most inexperienced guy in the room.

Now that I'm, well, not the youngest guy in the room, I'm a lot more comfortable with my mistakes.   Here area few of the lessons I've learned the hard way.

Success is Situational -- Because someone was successful at one thing (company, product, role, whatever) does not necessarily mean that they'll knock it out of the park somewhere else.   Markets, resources, politics, and a myriad of other factors make every challenge unique.

The Answer Isn't Inside -- Early in my career, I just knew we could figure it all out with a whiteboard and a spreadsheet.  The story makes sense, yes?  The model looks great, right?  Yup.  Butprospectsdidn't care.  So guess what?  The product didn't work.

If Sales Doesn't Buy, No One Will  -- No matter what you do, if your Sales team doesn't believe, you're facing an uphill battle.  I used to think we could show up at a sales meeting with a slickPowerpoint and they'd run off and make my product a winner.  Nope.   Your first sale has to be to Sales.  When they believe, then the magic can happen.

Group-think is Real -- and it Kills -- Many times I've followed the siren-song of hiring people who don't challenge the status quo.  Or ignoring people who with an inconvenient view.  I've learned differences of opinion, when constructive and open, lead to polish.

Sometimes Convincing Takes Time -- I used to think that the power of my idea, combined with well crafted words or slides, would let me turn the tide of an organizations.  Nope.  Especially in larger organizations, but even in smaller ones, acceptance takes time.   I've learned to invest the time to "sell" my ideas (and be open to differences of opinion).  I figured out that if I discussed my ideas openly and frequently, that they became "our" ideas -- and things worked much better.

Sometimes the Good Stuff is Badly Packaged -- It's often been easy for me to dismiss someone's view if I didn't like the way they said it.  Or, quite honestly, if I didn't like the person very much.  But sometimes the kernel of something great is in there.   I'm learning to try to parse the words, separate the emotion, and see if there is something I can learn.

My Opinion, While Mildly Interesting, Doesn't Matter -- I've learned it's always better to describe facts and market feedback than to express my opinion.  In the end, my opinion is only a hypothesis in an experiment.  Prospects are ultimately the arbiters of the results.

Politics Matter -- I used to think that ideas could categorically overcome organizational politics.  Turns out organizations are made of humans and humans have agendas.   When I take the time to understand others' true motivations -- including those under the surface,  things generally go more smoothly.

Turns Out, I Have a "Gut" --  Not the kind I'm trying to work off by running, the intuition kind.   Early in my career I droveback from a big meeting about a big deal with my boss.  He asked me what my gut told me about the deal.  I hemmed and hawed about internal rate of return and cash flow and a bunch of other MBA bullshit.  What I was (poorly) attempting to mask is that I didn't have a "gut."   Now that I've seen a lot more successes, failures, and just plain odd things in business, I definitely have a gut.  Generally, when I trust it, things go reasonably well. When I don't, I later find out why I had a bad feeling to begin with.

When You Screw Up, Don't Bury It -- Man, it's tempting to hide that misstep.  Or to paper over it.  Turns out, mistakes are human.   I've learned it's much better to admit it, figure out what I learned from it, and move on.