As I recognized the woman—who I hadn’t seen in years—my mind raced with intense associations. I shuffled to their table to say hi. Ten years earlier, the woman had been the communications director for the local school district where I sat on the board. She had been particularly sensitive to my PD, and kind in her concern.

When we last spoke, it was 2014 and Deep Brain Stimulation (DBS) surgery neared. The procedure had a high, but temporary success rate, with symptoms usually re-emerging five...