Do all guys do this?

Like I don’t know if this is common, but when guys get a girlfriend they just go into child mode. Like they’ll still act mature but they just become little children again. I literally just got a girlfriend and every time I’m with her I’m just happier than usual. Like we went to a restaurant and I asked her if I could get a milkshake and she smiled and said sure. My heart literally exploded in that moment.