I've been
saying for a while that I needed to put up pictures comparing Sam sewing himself up in "Mystery Spot" and "I Know What You Did Last Summer," because there's a HUGE difference in how he reacted to the pain, and I think it shows how much an influence Dean (even a faux-Dean Ruby) made. Here, look:
Here's Sam having just removed the bullet from his side in "Mystery Spot."
ETA: And really? That right there is where I started turning into a Sammy-girl. Because HOMG how bad do you have to be hurting for BULLET REMOVAL not to hurt you????? And, you know he still remembers all that.
And this is Sam sewing up his arm in "I Know What You Did Last Summer."
Sam cleaning the wound with peroxide in MS and whiskey in IKWYDLS: