If it helps any, paraphrased here is how I had post-op abdominal pain explained to me: The nerve supply in the abdomen exists mainly to support digestion, elimination, and the lives of the organs that carry out these functions. Those nerves are pisspoor at accurate transmission of pain. Same in the thorax. That's why people feel like they have indigestion when it's a heart attack, or nausea when the abs are just exhausted from to many sit-ups, or get sharp, debilitating pain ( or roving aches or u-name-it) during healing.
I can't vouch for its accuracy, just that it's how an MD explained it to me.
More physical activity improves the messaging (decreases foolish signals) but it'll likely be months to years until one day you realize you haven't had this or that weird pain for the longest time.
Happily, bad anniversaries do pass. It's good to indulge your emotions a fair bit for the first one--part of processing it all.