I had two friends, one who breast fed her son until 5 at naptime. My own son was disturbed that his bud was doing that.
The other was a mom who just couldnt wean her kid. Finally one day she looked down and he was noshing on a sandwitch and taking sips and she said enough is enough.
I think it was about the closeness and comfort in both cases. Both are wonderful women in so many other ways.
Both were elderly moms, in their 40s too.
I had to stop my son nursing at one year because he was biting like a Rottweiler.