Great memory! It's wonderful to know that our mountains were being enjoyed back then.
To answer your question, a "46er" is someone who has climbed all 46 of the designated Adirondack High Peaks. These must be documented climbs, and a letter must be written and sent to the Adirondack 46er organization. Then they'll start a file on you and as you climb each mountain and document each climb, they'll add it to your file.
So you've only got 45 more mountains to go!!
Loved your story - thanks so much for contributing.