There’s something you may be doing every day that’s making you look old. And you probably have no idea what it is. It’s not your clothes, your hairstyle or the AOL email address you’re using (although those aren’t helping either).

What you’re doing is subtle, and worst of all, it’s what you were taught in school. How could someone teach you to do something incorrectly? Times have changed, possibly without you.

Before I get on a high horse, let me share – I learned this lesson the hard way. I want to keep you from learning it the hard way, too. Because it’s possible nobody else will point it out to you. They’ll just talk about you when you’re not around or wonder to themselves about your intelligence.

This is how I learned my lesson the hard way. When I wrote my e-book, “Breaking The Rules & Getting The Job,” I used an editor who read the 100 draft pages in detail. When she finished, I asked for feedback on my writing style. She said something I never expected to hear. “The one thing you need to stop doing is using two spaces after your periods.”

Wait, what? Nothing about my writing style? Two periods instead of one? But, teachers in school drilled two spaces into my head. “This must be a minor creative difference,” I thought. I left the e-book with double spaces and never looked back.

About six months later, I met with another group of editors who review my column. I asked the same question.

One editor cringed. “Your writing style is good. But, there’s one thing that would be great if you could stop doing. You use two periods at the ends of your sentences. We always delete them.”

This stopped me in my tracks. How in the world was this a thing? How was it a big deal? How was it a pet peeve of writers? Where did I go wrong?

From the best I can gather, using two spaces was taught for years in school. At some point, the standard changed and one space became the norm. Unless you write for a living, you probably weren’t told about the change.

Simply put, your two spaces are dating you. Anytime I tell a client about this standard, they’re always surprised.

Recently, I read an article that began, “Can I let you in on a secret? Typing two spaces after a period is totally, completely, utterly, and inarguably wrong.” The author goes on to say, “What galls me about two-spacers is…”

What I’m getting at is one space versus two spaces is apparently a controversial issue. And, we’re all being judged. If you’re out there applying for jobs, take my advice: Switch to one space. Don’t overthink it. Just do it. After some practice, it will become more natural. And you’ll look that much better, and younger, in job interviews.

Angela Copeland is CEO and founder of Copeland Coaching and can be reached at CopelandCoaching.com.