1) It's healthier- Coming home is supposed to be the start of something else. Taking time to rejuvinate, and hang out with your family is healthy, and if you leave your work at work, you will be able to sleep better because you won't think about it. At least I don't
2) Balance is key- Any working professional will tell you that they most important/difficult part of being in the work world is maintaining a healthy balance of work life, family life and self. Bringing your work home distrubs that balance. Like my dad always said growing up, "There is a time and a place for everything."
3) It's not billable- This is not meant to sound mercenary but the fact of the matter is that billing work is a part of our (PR) profession. It is expected that we learn how to do it, and it results in us accurately accounting use of our time for clients. Also people should be paid for the work that they do, and you don't get paid for things you do on your own time. (Likewise, don't do on your work time what should be done at home)
Now since I've gone and ruined your fun, I'll share a few ways to increase productivity at work without bringing work home:
1) At the end of the day, make a to-do list for the next day before you leave. That way, there's no dilly-dallying (love that word) while you try to figure out what's on the agenda for the day, you can jump right in!
2) Keep a notepad or word doc open throughout the day to jot down random ideas that are not applicable to what you are working on. That way, you don't lose them, but you can keep on task.
Any other ideas? What do you do to keep productivity up while at your job/internship?