Yeah it is only part of your life, you don’t have to live in the lab or anything. We get lots of free time and in research the hours are very flexible. I play on a soccer team, spend time with friends and family, watch Tv, play xbox all the normal things people do.
When I started my PhD I spent a lot of time working, and not a whole lot else. But that is a bad idea because you will burn out really fast. You have to mix hard work with fun- otherwise you will go crazy. By the end of my PhD I have made it a 9-6:30 job, with a bit more studying outside of work. Now that I am transitioning to working as a postdoc researcher, I intend to keep do the 9-5 thing and treat it as a normal job as much as possible. Also I just got engaged, so I will get in trouble if I spend too much time working 🙂
Some times it is hard though because there are so many interesting projects to work on!