Dan and his younger brother, Mike, are about 18 months apart. Dan had curly hair, Mike had straight. Dan was passive, Mike was aggressive. Dan was timid, Mike was a daredevil. You get the picture.
When you look at their two sons you see their mini-me's. Ryan looks (and acts) exactly like Mike did. Fisher looks (and acts) exactly like Dan did. It was fun to have Ryan here for a week while he visited from Texas. I can't exactly say that he and Fisher got along famously (again, like Dan and Mike), but they sure loved the idea of each other!