My challenges with comprehending a new recipe

Earlier today, I attempted to follow a new potato recipe. The recipe read, " Cut potato in half. Brush both sides of potato slices with butter; place them on a cookie sheet." I saw a picture, but I hadn't realized that I was supposed to cut the potatoes in half lengthwise, so I cut them the other way. After a short time, of baking, I showed them to my boyfriend and asked if I should slice them. He looked at the potatoes and he said that I had cut them the wrong way. We took the potatoes out of the oven and he cut them in half the correct way. Later, I apologized for making a mistake and he said that it wasn't a problem. This is just another example of how challenging my comprehension can sometimes be. I wrote on the recipe card, " Cut potatoes in half lengthwise." Hopefully the next time this will help me make them correctly.