I thought this was a really great movie and it definitely had some posotive messages. The movie is relatable and helpful for some. The movie did have some sexual scenes & swearing throughout and wouldn't be appropriate for most 13 year olds but it's definitely fine if they have matured. Any older should understand the context. The humour is definitely subtle but watching it a second time you should pick it up. Personally I thought it was really funny. I've watched it 4 times since the first.
This movie should have been rated R. It is totally inappropriate for young kids. As a teen, it is simply scalding. The message isn't great, and the junk that you have to go through to get to the message makes it worse.