In high school, Siri and some friends were studying for exams and in fits of rollicking laughter (to this day, she can't tell you what they were laughing about). My sister was laughing so hard that her forehead rocked forward and downward, right onto the sharpened pencil she was holding in between her hands (who holds a pencil like that anyway???). With blood trickling down her face and the broken tip of the pencil lodged in her forehead, she laughed even harder while her friends literally rolled on the ground. There wasn't a hospital visit, just parents shaking their heads in disbelief, and she kept that tiny piece of lead stuck in her forehead until it healed over.
Today there's a whisper of a minuscule divot as evidence of her hilarity. Even though it's unnoticeable, it always reminds me of my sister's enviable ability to laugh with such abandon and finding even more humor in the face of pain and humility.
PS - She doesn't know I'm telling the interweb world this story. If she knew, she'd probably punch me in the face