Because that's what most fathers do...

Also they just finished their pappaperm which they said was 133 days over the summer and that means their child likely started in nursery in August or September as is the child's legal entitlement if they were born before August last year or in September last year...

I get that you did something different but the OP's case really does sound like they did what most Norwegian fathers do... (I'm not knocking it because that time was truly special for me.)