If you've got time on your hands then for goodness sake, enjoy it!!! I wish I was in vacation still... Anyhow you can't do anything about it at this point so don't worry about it.
Take a moment to enjoy life cause you are signing up for 6 years of slavery
Here is a suggestion: find something new that you like to do - a new hobby. I did that this break. I figured it is about time i took an actual break where I am not reading physics or something related. I picked up a few fun books. Started knitting (I know I look like a granny). Anyhow enjoy.