Changes are huge
I once had a friend who had a hard time making some decision. She made it, changed to another one and later told me that she didn't feel happy.
I asked her "you had a choice, you made ur choice, why complains now ?". And we didn't talk with each other since then.
I'm usually quite sociable (read: crack stupid jokes with my friends when we were hanging out)
I went to some birthday party yesterday where I didn't know anybody but one. Felt quite uncomfortable. Talking to people in the environment you're familiar with is very different with talking to people in another environment. You never get how much different they are, until you were there.
I once sat at some bus station in Tokyo, about to depart to another city. I felt a bit nervous because the ticket, the information board and all the people were Japanese with no little sign of English. Felt kinda lost
I felt nervous and also excited
Changes are huge
And I'm eagerly-miserably-simply longing for it : )