So you've decided to be a language teacher!

[sitifan]

So you've decided to be a language teacher!
What does 'so' mean in the above sentence?
Thank you very much for your reply.

PS: It is the first sentence in Chapter One of a book entitled "Teaching by Principles", written by H. Douglas Brown. There are no foregoing sentences. So it does not mean "therefore."

[guzhao67]

I'm not a teacher.
here it's used to get someone's attention, especially in order to ask them a question. another example: "So, how was school today?"

[Raymott]

Yes, it's also used to signal a change from general chatting to something more serious or more important to the speaker:
A father talks to his daughter for a while about unimportant things, then says, "So, your mother tells me you're pregnant."
The word "so" here is more a functional particle than anything meaningful.