John Lennon was raised by his Aunt Mimi, who is usually described with words like “strict but loving.” And while there is some debate among Beatle people over exactly how “loving” she really was, nobody questions the “strict” part. As you can imagine, then, she was not a big fan of young John’s obsession with rock and roll, or his non-stop guitar practice.

“The guitar’s all well and good, John,” she would say, “but you’ll never make a living at it.”

Years later, when John was a rich and famous Beatle, he had those words engraved on a plaque and sent it to Aunt Mimi.

“The guitar’s all well and good, but you’ll never make a living at it.”

We all have our Aunt Mimi’s, don’t we? If your vision, your goal, your dream is big enough to truly inspire you, then somewhere along the line you’re going to run into somebody who doesn’t believe you can accomplish it. It could be a family member, a co-worker, or the person sitting beside you on the airplane—maybe even all three. And the thing of it is that logic actually favors the naysayers. The odds probably were against John Lennon ever making a living with the guitar. I mean, c’mon—how many kids dream about being a rock star? I certainly did, and I’ll bet you did too (and if you didn’t, you probably know somebody who did; plus, I think you’re lying). But the number that really make it is ridiculously small. That’s because it’s really, really easy to have a dream, but much more difficult to actually attain it. It takes ambition, talent, hard work, and a hundred other elements. So the naysayers do have a point.

But here’s my point. Some people do achieve their dream. Some people do fulfill their vision. And these people are never the ones who believed the naysayers. The people who achieve greatness—whatever their definition of “greatness” may be—are the ones who hear the naysayers, nod politely, and get on with the work of achievement.

John Lennon heard his Aunt Mimi and went on practicing. He heard his Aunt Mimi and formed a band. He heard his Aunt Mimi and made some records. He heard his Aunt Mimi and changed the world.

Imagine if John Lennon had heard his Aunt Mimi and believed her. Imagine if John Lennon had bought into all the naysaying. Imagine if John Lennon had given up on his vision, his dream. If that had happened, the world would never have heard songs like In My Life, All You Need Is Love, or…well…Imagine. The only reason those songs—and dozens of others like them—exist is because a kid with a vision ignored the naysayers and got to work.

What’s your vision, your dream? How badly do you want it? Badly enough to ignore the naysayers (and, by the way, many times these naysayers reside in our own brains—and they can be very persuasive)? Badly enough to get to work and do what’s necessary to achieve it?

Because, let’s be honest, the truth is that you may or may not achieve your dream. The bigger the dream, the bigger the obstacles. It’s probably not going to be smooth sailing. Nobody can guarantee your success. But what I can guarantee you, with 100% certainty, is this: you’ll never achieve your dream if you let your own Aunt Mimi’s get the better of you.