Last week, I was in lurking in the back of a room (which is usually where you’ll find me), listening to a rather successful entrepreneur give a talk to a bunch of young entrepreneurs, most of whom were students. At one point, he made this careful distinction:

“I’m not that guy. I’m not the visionary. I’m the number two. I’m the guy that you give me the idea and I’ll get it started.”

He then asked how many Number Twos were in the audience. Given that the room was full of students, and that most young entrepreneurs think they’re the second coming of Elon Musk, I expected crickets. Instead, much to my surprise, several hands went up, including one young entrepreneur who had made a presentation earlier in the evening.

I was aware of the distinction, of course. The Number Two is the person behind the founder or founders who takes the idea and creates the product or gets it to market or otherwise makes it tangible and successful.

But I had never really given it much thought. Like most tech-founders or tech-CEOs, I’ve been both the visionary and the Number Two, sometimes at the same time, for the entirety of my career. I’ve had pretty much equal amounts of success and failure in both roles.

So I tend to take that distinction for granted. I had certainly never heard an entrepreneur with a solid amount of success admit to being “just” the execution guy.

Everyone loves the idea, the home run, the slam dunk. But the world wouldn’t move without the producer. Think of Moneyball and Brad Pitt’s Billy Beane begging a team of has-beens and never-wases to focus on getting on base. Closer to home, think of Dean Smith and the tradition he created to “point to the passer” when a star player scores.

Again, with my background, I’ve never really thought of the terms “founder” and “entrepreneur” as interchangeable. A founder is someone who is necessary to start the company. An entrepreneur is anyone, including the founders, with a larger than nominal stake in the success of that company, and who spends all their working hours finding ways to make that company succeed.

Low-level or later stage employees, I usually don’t consider them entrepreneurs because they didn’t take the initial risk of failure. Investors, mentors, consultants, advisors and those types — they may have been entrepreneurs at one point, but they’re not playing the entrepreneurial role now because it doesn’t consume them the way it does, say, the management team.

But the Number Two is not only an entrepreneur, he or she is just as important, if not more so, than the visionary.

Ideas, as it is said, are a dime a dozen. I had a nickel’s worth on my way to work this morning. As an entrepreneur who has been a founder, I never stop thinking about ideas, whether they’re just-so-crazy-it-might-work startup ideas or simply ways to better the product I’m currently working on.

But if I had six startup ideas this morning, I’ve probably brought exactly six startup ideas successfully to reality in my entire career. Ideas are easy, it’s the execution that makes the entrepreneur.

Oddly enough, that’s the exact title of a talk I gave a few months ago, but I wasn’t thinking in terms of two different people.

And I don’t think I’m the only one who has been overlooking the Number Two. When people break down roles on a founding team, they usually talk business skills vs. tech skills or maybe building skills vs. selling skills.

I’ve very rarely heard of idea skills vs. execution skills, but this is actually what the equation needs to sum out to. Not that those things are always mutually exclusive or all-encompassing, but you give me an idea-person who can sell paired with a tech-person who can execute and I think you’ve got a winning combination.

It makes sense to find out which one you are (or are you both), before you start down the road of serious startup (i.e. before you start spending money). If you lack one, go out and find the other.

And make sure you take care of those Number Twos. Otherwise, you’ll be looking back at that great idea that could have been the next big thing.

If only you had gotten it off the ground.