A few things I have learned

Three-year-old boys and white shirts are not a good combination.
Always stop at the bathroom before you pick up a crying baby early in the morning.
You can use baby shampoo to wash nearly everything.
Neat piles are actually very attractive in a home.
You can jog with a newborn in a regular stroller. You don't need a jogging stroller.
Sit on the floor and play.
You will neglect your pets when you have a baby.
Your car will develop some kind of funk, no matter how anal you were before you had children. If you had a messy car that was dubbed "Kitty Box" before you had children, your car will be condemnable. How condemnable? Take the number of empty cups you had in your car regularly before you gave birth, multiply that times the number of kids you now have, and divide that by how many showers you take each day. That is how many unidentifiable gook-covered sippy cups you will locate in your car each month.
Your children will find the one breakable part of any object. Accept that and move on.
Don't try to sort toys. The moms in the playgroups will tell you to. Ignore them.
Play with your kids in the swimming pool. Don't sit in a lounge chair and watch them. Bonus points if you get your hair wet.
It's okay for kids to go barefoot on the beach.
Those shopping cart cozies are just weird.
Quit watching the birthing shows on Discovery Health when you are postpartum. Watch your baby instead.
Also, if you happen to be postpartum when PBS is airing "The War," keep changing channels.
Your kids will drop things in your bottled water which you will find like a worm at the bottom of a bottle of tequila.
Invest in a Lazy Boy before you reach your third trimester of pregnancy.
Do not read baby books cover to cover. Keep them around for mere reference. You will know what to do most of the time.
Babywearing is not easy in Louisiana in August.
Speaking of babywearing, if you do choose to wear your baby, get at least 10 different kinds of baby carriers.
You don't have to put the batteries in.
Don't try to cut your baby's hair yourself.
Wait until your baby is choking on hair to cut it. Otherwise, you'll end up with a 'do that the priest dubs "Tres Moderne" at your child's baptism.
Kids love backyard swimming parties. Skip the house-sized inflatables until they are old enough to ask for one.
And lastly, whatever you think you can accomplish while carting a baby is probably possible, but could cost you your sanity.