DEAR MISS MANNERS: Not being naturally good at conversation, I’ve learned to look for specific cues that an exchange has been going on too long or that I need to move on. An obvious cue is when someone looks at their watch. However, many people in my life now wear smartwatches, which alert them if they have a new text or email. Consequently, people are constantly glancing at their watches to triage incoming messages. This happens during both formal and informal conversations, at work and when chatting with friends. Each time, the gesture kicks me into “It’s time to wrap this up” mode, even if …