Have you ever felt incredibly sexy and confident, only to take a photo of yourself and think that confidence to be woefully misplaced? You're not alone, but your photo is also not an accurate indication of how you actually look. Our friends at YourTango [1] explain why we hate photos of ourselves, according to science.

Mirror, mirror, are you lying to me?

You check your makeup in the bathroom mirror before you head out. Perfect! You take a selfie to immortalize your look forever, but you don't have time to make sure the selfie came out OK because you're already running late. Later, when a friend asks to see a different picture, you scroll by your earlier bathroom selfie and you're horrified.

Is that how you really look? What you thought was perfect is actually a big mess. How could you have been so wrong, and why do you hate the way you look in photos?

The problem is that most of us are used to seeing ourselves in mirrors, and unfortunately, the mirror lies. When we look at ourselves in a mirror [2], we might think we're seeing how we really look, but we're actually seeing an inverse image.

Most people's faces aren't absolutely symmetrical [3], but that's OK; we get used to seeing how their left eye is slightly larger than their right, or how their smile seems to turn downward. After years of looking in the mirror (pre-teens spend half of their lives doing this), we get used to the face staring back at us. And this is where mere-exposure [4] comes in.

Mere-exposure (developed by a psychologist named Robert Zajonc) shows that people react better to things they see more often. Zajonc found that mere-exposure works on everything from facial expressions to nonsense words. We like what we're used to seeing, so it makes sense that we prefer the image of ourselves that we see all the time — the image with our flipped facial imperfections.

According to the mere-exposure effect, when you see a photographic representation of your face unflipped by the mirror, it looks odd to you, off-kilter and kind of strange.

But before you swear off selfies, make a promise to yourself to only take Snapchat selfies. Why? Because Snapchat doesn't flip the image to its inverse; it takes a photo of you that you know and love.

More great stories from YourTango:

• Fun Facts About Penis Sizes [5]
• Reasons to Love Your Little Boobs [6]
• You Can Get an STD Even If You Aren't Sleeping Around [7]