I will be the first to admit that whenever I see the television advertisement in which a mother cries in joy as her perfect, smiling baby strokes her face with his tiny finger, my biological clock not only ticks - it positively erupts. Then I spend a full day with a friend who has a real baby.
I expect that at most a young man would respond to the ad by thinking "that's nice". It would never enter a young man's mind to rush off to a friend's place to spend a day with a real baby.
Just one more small example of how different men and women are, especially in our instincts toward motherhood and fatherhood.