Account login in Chrome feels too insecure?

On my son's recommendation I've decided to give 1Password a try and have been getting an initial feel for the family trial version this afternoon.

I like it apart from one thing. I've added the 1Password browser extension which is very slick. However, when I open the Chrome browser and want to login to my actual 1Password account, 1Password helpfully offers to fill in my master password and with just a click I have logged in with full access to everything, passwords, secret key, the lot.

This is great, but wouldn't be too good if my house had just been burgled and the thief had stolen my PC. He would be able to access absolutely everything with relative simplicity.

I'm sure I'm missing something here. Perhaps I've done something wrong when setting things up? Is there a way I can at least force the master password to be input each time I open Chrome. I feel a little uncomfortable with the current setup.

1Password Version: Not Provided
Extension Version: 2.13.0
OS Version: Windows 10
Browser: Chrome