A forgotten name does not necessarily mean the encounter mattered little.

Names are stored differently from everything else, which is why you can recall what someone said, where they stood and how the conversation turned, while the name is simply not there. Losing it feels like an insult you have accidentally paid them. In fact the meaningful part of the encounter is the part you kept. A name is a label, and labels come off more easily than contents.

When you cannot retrieve one, say so plainly and ask, rather than avoiding the person for a year. Most people are relieved, and the alternative costs far more than the moment of asking.