People are always saying this about their children. However, it’s very sad to me. Usually people say this when they haven’t seen your kids in awhile because of the lapse in time periods makes it seem as if the child is growing at an alarming rate. It’s even worse if a parent says this about their own kids. It makes me think that you are not paying attention to your kid. Unless you are injecting your kids with HGH or they have a pituitary gland disorder then your kids are probably growing at a normal pace for a human. Or maybe it’s just a figure of speech, who knows!