I've had 2 heart surgeries, and before the first one I explained to them that I was in recovery and worried about becoming addicted to the pain medications. They explained to me how important it was to stay ahead of the game managing pain, because once it got out of hand it was very difficult to get it back under control. Therefore it was important early on to take the pain medication as prescribed even if I felt I didn't need it.
I didn't listen the first time around and ended up with complications that caused chronic pain (sternum didn't heal properly). I was on pain meds for over 3 months and sure enough I ended up physically addicted to them. After the 2nd surgery I let the doctors make the decisions and I was off all pain meds within a week of having the surgery.
My point is that even though it is wise to be cautious about taking pain medication, it's also wise to defer to our doctors and trust that they have our best interests at heart.