How many times have we been told that someone is so certain of their directions because they know the place like they know the back of their hand? For most of us, I imagine the answer would be countless times.

Personally, I don’t know that I’ve ever said it—mostly because I think it’s a stupid saying. But if I’m honest, I’ve always wondered just how well I ‘really’ know the back of my hand.

Well, today (yes, I’m bored!) I decided to see just how well I know the back of my hand. And—lucky you!—you get to see the results.

I chose my left hand because that’s the one with the most stuff on it. To start with, I traced my hand onto a piece of paper then I allowed myself a few moments to study my hand. No more than 10 seconds or so. Next, I placed a glove on my hand to ensure I wouldn’t cheat.

Then I began to sketch a map of my hand. (This was a bit difficult with a glove, but I wasn’t going for perfection.) I decided that I would include major veins, freckles, specs, and scars. Then I decided to add approximate locations of joints and knuckles.

The results? Pretty bad, I think—especially if I plan to use the memorisation of my hand as a correlation to my abilities to give directions!

For starters, my knuckles are actually further back than I drew them. (The other finger joints seem close enough.) Next, my fingernails are not drawn at representative sizes. Moving on, the veins are wrong. The main one (the Y-shaped one) is fairly close, but the other two I have shown are pointing in the wrong direction in relation to my fingers. Oh! And there are a couple of veins that seem to have been missed out all together.

Then there are my freckles. OK, the two large ones in the centre are pretty accurate, but there are four others on the back of my hand that (whilst very small) went completely unmapped. Oh, then there’s this little red spot on my thumb that’s been there for years but isn’t actually a freckle. Apparently, it’s nearly on top of my thumb’s knuckle, not toward the thumbnail!

The scar I have shown actually curves the other way. (It’s not that noticeable, either.) Also, I failed to make note of other small scars.

So, do I know the back of my hand very well? No, not as well as you’d think, given it’s been attached to my arm since before I was even born!

How about you? How well do you know the back of your hand?