When I was single, I left the bathroom door open because no one else was around. When I go married, I left the bathroom door open a bit to hear my wife if she asked a question. Now my kids leave the bathroom door open and I can't lock it for fear of interrupting the potty training process.
When I was younger, and someone new was moving into the neighborhood, I hoped they were an attractive young woman. Now I hope they have kids the same age as mine.
A night off used to be a chance to party. Now it's a chance to sleep.