My son turned 11 in July. He started middle school this year, or what I like to call the "Year he stops being an innocent kid.".
Life lessons are already smacking him in the face this school year. He's changing by the day. No longer the "little guy" I love.
But I take pride and pleasure in watching him become the young man he is.
All I can do is guide him and offer advice and pray he doesn't turn out like some of the other kids I see today. Middle school is a different, more violent, connected (internet) and dangerous place than when I was in.
Although part of me can't wait for him to grow up so I can see what kind of man he'll be, another part of me wants to keep him at this age for the rest of his life. Where he's independent for the most part, but still needs "his Daddy".
EDIT: One thing I did learn fast, part of the reason we as parents think they "grow up so fast" is becasue we tend to get trapped in thinking they're still 5 when they're 6, 7, or 8. We dwell on it, not necessarily on purpose, but to try and keep them young I suppose. Then one day we realize all the time has passed and we readjust to their current age and demeanor and repeat the "hanging on to the past" process all over again.