When I was about 21, I felt a hard place at the top of my right breast. Of course, I started worrying that I might have breast cancer, but I was too scared to call the doctor about it. But when I went for my next check-up, I told him I found a lump. He felt it and said, “That’s not a lump. That’s your muscle.”
“But it’s on just one side.”
“You're right-handed,” he said, “so your muscle is more developed on that side.”
I felt like a fool, and my doctor’s...

