One of the kids in my swimming class was terrified of the deep pool. I found his mother sitting poolside and asked if he’d had any traumatic experiences that might have caused it. “No,” she replied. “It’s me. I’m afraid of the water. I won’t even go in up to my knees.” She’d had a near-drowning experience in her early twenties and hadn’t been in the water since. To help her son with his fear, though, she agreed to work with me on her own. That’s how I felt entering the dating pool again after 15 years of marriage — I was too afraid to even go knee-deep. My close group of friends after divorce were all single women. They were younger than me and using Tinder most weekends. They made it look easy and, hanging out with them, I started to wonder if I was ready to get my…