Here is something nifty and important to know

It is okay to say, "No, I'm sorry. I can't listen to you right now." It is okay to say, "No, I'm sorry. I can't talk about that right now."  You are under no obligation to be perpetually prepared for whatever conversation people want to have with you, and it is sometimes smart and right and prudent to avoid conversations you are not prepared for.

From the "File of Things I Wish I Knew A Long Time Ago" (Cross reference: "Things I Really Need To Remember" File)