As a postgraduate, your college plays a different role in your life than for the undergraduates. In general, your college plays a support and community role – much of the actual teaching happens in your department or at the college where your supervisor is based. I’d generally start my day by visiting the MCR to make a coffee and have a chat, before heading to my department to work. Pembroke’s library is also extremely useful, and had a huge number of books I needed for my politics and international relations papers (and they will always try and order hard to get books for you!)