Random thought...

When I run into something (I find myself doing this a lot lately) and it really hurts I often respond with, "that's going to leave a mark!" Yet I find it interesting that those scenarios never actually do leave a mark. However, I will find random bruises on my body and have no idea how they got there. Why is this? The other day my husband's eyes got large as he asked where I got the big bruise on the side of my leg. I had no clue I even had a bruise there let alone how it got there. Isn't that weird?