Random bits and pieces I have learned along the way...

• There is always someone at LBS who knows the answer to your question. 
• Don't mass post on discussion boards. It's really annoying. You don't want to be that guy / girl.
• There are other pub options in NW1 besides the Windsor.  Try the Swan & Edgar.
• Though you think it won't happen, you will talk about the weather. A lot. 
• There is occasionally nice weather in London.
• There are very few secrets in the MBA.
• Though you try to fight it, you will use British phrases - e.g., I now fancy things. Also, see "bits and pieces" in blog title. Another British-ism I've picked up along the way.
• There is such a thing as Club Conference fatigue. You don't have to do everything in autumn term.
• You will make friends from pretty much all over the world. Diversity = LBS.
• First year really does fly by.