At a recent event hosted for founders by the venture firm Village Global, one of its most prominent investors, Bill Gates, sat down with Eventbrite cofounder and CEO Julia Hartz to discuss founding a company and the tough decisions necessary at nearly every turn in order to create and sustain a thriving enterprise.

As part of that conversation, Hartz asked Gates about his views on work-life balance, and whether they have evolved from an earlier point in Gates’s life, when he has said that he “didn’t really believe in vacations.”

His reply, in short: no, not in a company’s earliest years and especially not if that company is building a software platform. As Gates told Hartz, “I have a fairly hardcore view that there should be a very large sacrifice made during those early years, particularly if you’re trying to do some engineering things that you have to get the feasibility” or proof that a project can be performed successfully.

In fact, Gates is still kicking himself for taking his eyes off the ball and allowing Google to develop Android, the “standard non-Apple phone form platform,” as he describes it. “That was a natural thing for Microsoft to win.”

You can find their entire chat below, but here’s Gate’s full response to whether he thinks it worth it to focus narrowly on work or whether early-stage founders can strike a better balance:

I think you could over worship and mythologize the idea of working extremely hard. For my particular makeup — and it really is true that I didn’t believe in weekends; I didn’t believe in vacations; I mean, I knew everybody’s license plate so I could tell you over the last month when their card had come and gone from the parking lot — so I don’t recommend it and I don’t think most people would enjoy it.

Once I got into my 30s, I could hardly even imagine how I had done that. Because by then, some natural behavior kicked in, and I loved weekends. And, you know, my girlfriend liked vacations. And that turned out to be kind of a neat thing. Now I take lots of vacation. My 20-year-old self is so disgusted with my current self. You know, I, I was sure I would never fly anything but coach and you know, now I have a plane. So it’s very much counter revelations and taken place at high speed.

But yes, it is nice if during those first several years, you have a team that has chosen to be pretty maniacal about the company, and how far that goes, you should have a mutual understanding, so you’re not one person expecting one thing, and another person expecting another thing.

And you’ll have individuals who, who have, you know, health or relatives or things that [distract them]. But yes, I have a fairly hardcore view that there should be a very large sacrifice made during those, those early years, particularly if you’re trying to do some engineering things that you have to get the feasibility.

You know, in the software world, in particular for platforms, these are winner-take-all markets. So, you know, the greatest mistake ever is the whatever mismanagement I engaged in that caused Microsoft not to be what Android is, [meaning] Android is the standard non-Apple phone form platform. That was a natural thing for Microsoft to win.

It really is winner take all. If you’re there with half as many apps or 90% as many apps, you’re on your way to complete doom. There’s room for exactly one non-Apple operating system, and what’s that worth? $400 billion that would be transferred from company G [Google] to company M [Microsoft].

And it’s amazing to me, having made one of the greatest mistakes of all time — and there was this antitrust lawsuit and various things that, you know, our other assets, Windows, Office,  are still very strong. So we are a leading company. If we got that one right, we would be the company. But oh well.

So this idea that just small differences can magnify themselves doesn’t exist for a lot of businesses. You know, if you’re a service business, it doesn’t exist. But for software platforms, it’s absolutely gigantic. And so that’s partly where you have the mentality of every night you think, ‘Am I screwing this up?’ And eventually, we did screw up a super important one.