Knocked Up." No, no, no. That is the reason why so many people had lots of not nice things to say about this movie which is actually quite good if you know what you're going into. Sure, we met Paul Rudd's family in Knocked Up but This is 40 has very little of the same style of comedy as that movie. I would say if you go into this movie with the same kind of mindset you would go into with another Apatow film like Funny People you should be okay.
What I liked about this movie is how easily I could relate to it. You could feel the balance of love and hate between Leslie Mann and Paul Rudd as a very believable married couple. Their children (played by Mann & Apatow's real-life daughters) stole the show by being both amusingly funny and heartbreaking. That's what makes this movie great. How real it felt. I went from laughing to crying several times during this movie and I can only think that the negative comments about this movie have to be coming from single, childless people who really don't know how simultaneously wonderful and terrible being a spouse and a parent can be.
*Side note? I love how Husband's comments still live on in those links I provided for my older movie reviews. Sigh.