I don't treat DD 2.5 like an adult, though. We are very, very silly and I don't expect her to always understand or control her tears.
I myself was treated like I was way older than I really was, thanks to my language skills and giant size, and I think I missed out on being a carefree kid. I don't want that to happen to DD.
I think you have a really good point there. I know that it is hard with gifted kids as they often act much older than they are and communicate as they are, but I still remind myself even with my almost 5 year old that he is still a kid and needs that playful silliness. It is really important. So I mess around and play with him often. Sometimes I am sure he thinks I am crazy, but that's okay. Sometimes it helps him to be a little more relaxed and playful. It has helped him to branch out a little bit.