Lots of people will tell you “oh it’s so fun having a kid. Little Johnny sleeps through the night, he does so well in his car seat, we just got back from the mountains and he loved it, etc.”
Well reality is not all sunshine and rainbows, and that’s normal. Be prepared for that. The great moments will be mixed in with the hard times. One of ours screamed bloody murder every time they were in their car seat for more than 10 minutes. That lasted about a year, and it made going anywhere pretty stressful. Had another kid that didn’t sleep through the night once until they were three. Also stressful.
Random things to expect…
Your spouse will probably buy all kinds of weird baby stuff off the internet that seems totally unnecessary.
When you go somewhere for the night, be prepared to carry in an inordinate amount of stuff. I highly recommend carrying it with a smile, and not asking what it’s for.
You are not going to agree with the wife on a lot of parenting things. Try to remember your wife loves your kids too, and no matter how stupid their choices may seem, they are probably doing the best they can, same as you.