How to stop a chrome extension from reloading upon every new page?

I am building a chrome browser extension which prompts the user, “Why are you on this page?” and then sticks the answer in a styled rectangle div which has fixed position on the screen.

Currently what is happening is: every time the user opens a new page, the window prompts them for a new answer.

Is there any way to:

(1) Prompt the user ONLY when they’ve first opened the browser, store that answer in a var,

(2) Keep the same var across all pages the user has entered?

So, say for example:

(1) The user opens google chrome. The browser prompts them, “What is your goal this browsing session?”

(2) The user types, “Find a quote for my essay.”

(3) Now, no matter what tabs or pages they open, there is a single rectangle in the corner of the page that says, “Goal: Find a quote for my essay.”