Honestly, I don't recommend Oslo. People from Oslo is a bit different from people from other districts..
Oslo people think they are the best people, and they like to comment everything. I don't hate Oslo people, but it is how I look them.

Somebody are very mad and rude too....

Example: One time I was in Oslo, i took a bus. Then I was unsure where we was, so I asked a randomi guy:
Where are we now?

The answer: Are you an idiot? Look outside!

I looked outside.
- Uhm, I dont know...?

- Oh my god, are you kidding me? This is Oslo central station!