Playing footy, running through a muddy field and my calf snapping doing it. Felt like I'd been shot and had to drag myself to the bus and travel for 6 miles getting home. Luckily my kid helped me as a crutch!
Being smashed into on my bike. Luckily after I flew into the air, high over the roof, I landed on my collarbone, not my head (I wasn't wearing a helmet). Months of pain and recovery.
Lastly, not quite pain, but after my sarcoidosis attack, I went down to about 9 stone in weight and walking 80 yards to the shops took more than half an hour, so return journeys were hell! I did my best to avoid them! Weird sensation, not quite pain as the disease attacked my nervous system, but then it was pure exhaustion instead.
Thought it was my last days on earth, back then!