I may well be BU, given that I tell people that DD2 is one when they ask her age.
However, the other day I met a woman I went to school with. She had her DS in tow. When I asked how old he was, she told me he was 41 months.
I have encountered similar in the past. Part of me wants to laugh and part of me wants to make a
face. What's wrong with saying he's nearly 3 and a half?
Or is this rare? Or am I being weird?