My LO just buttoned his sweater top to bottom the other day and I was so proud! I feel silly because I didn't even know he knew how to do it. He said his dad taught him, when I asked how he learned. When I asked DH he said he only showed him once a while ago. They were larger buttons, but still great to see him using his fine motor skills.
How old was your LO when they knew how to button things?