Socks

The problem being that I made the first sock in August, and I don't remember exactly what I did differently on the heel, but I know I changed something. As I turned heel on the second sock, if I followed the directions, I would have been left with 15 stitches, which seems wrong. So I didn't do the last p2tog, and I have 16 (a much better number). But when I did the first sock is that what I did? And did I pick up extra stitches at the corners and then decrease them away? I don't remember. Once again I'm reminded why I prefer to knit socks in parallel rather than serial.