If you hear a mom say their child is advanced for his age it's mom's way of bragging about their kid. A pretty transparent approach if you ask me.
My daugher got fabulous grades in 1st & 2nd grade and could have been in the "gifted and talented" classes in 3rd grade but her 2nd grade teacher thoguht she wasn't mature enough. I considered fighting that recommendation and putting her into the G&T classes anyway but realized it wouldn't matter in the long run. The teacher was right. So although she may have been "advanced" on an intellectual basis, she was actually delayed in terms of maturiity. As a teen she struggles with depression and other mental health issues and still has trouble developing relationships. The G&T program would probably have caused all kinds of problems for her. She is a bright kid and take some tough classes and does well - but being advanced doesn't make a difference in her life one way or the other.
My son, who has language based learning disabilities and had a really tough time in elementary school and still gets extra help now in middle school will probably excel in life becuase he is a very emotionally balanced person. So although he would be consdiered "delayed" for his age (academically) he is a go-getter, dynamic and gets along with everyone. So would we think of him as "advanced" for his age as it relates to social skills?
The term "advanced for his age" is really very nebulous. Studies have found that being emotionally well-balanced is a far better predictor of success in life than intelligence. In fact some of the really highly intelligent people I know have difficulties in life - it's almost as if they're too smart to deal with the rest of us! ;o)
So let's just all wait and see how our kids turn out. It's kind of like the author who wrote about having a child who was born with Down Syndrome - she compared it to planning a trip to Italy, seeing the Vatican, the colliseum, going to Tuscany, etc. but instead, ending up in Holland. And while the windmills and tulips are lovely, it's not what you planned. But after a while you learn to love Holland and the beauties of the place - although you still have wistful feelings about Italy.
Life is like that - we are in this competitive mode when our kids are in elementary school - we see how other moms seem to have it all together and we feel inadequate - or how other moms are so disorganized or their kids are just a mess and we feel better about ourselves. Then we get to middle school and high school and we realize that our kids are who they are, we have to help them discover their gifts and talents, and while they may end up being someone completely different than we thought they would be, if all works out well they will become the person God intended all along.
Don't worry about that mom referring to her kid as advanced. Pray that her child doesn't get arrested at age 16 becaue he is so "advanced".