I have given more emergency jump starts than I can count. Helped with a few flat tires, diagnosing a couple of breakdowns here and there.
My personal favorite was back when I had my old Saturn, I was heading home through the busy area of my town (The cops in my town are known for being asshats, and it has been that way since the decades preceding my birth) and I see a similar Saturn beside the road. Person sitting there, no lights. Nothing.
I turn around, talking to the driver revealed this unsurprising story. It's a light rain. The girl gets pulled over. Officer asks her to shut the car off. She explains that the battery isn't charging and it won't start up again. Cop makes her shut it off. Gives her a ticket/warning/whatever, sees that she can't get the car going again, and takes off, leaving her beside the road.
Right as I finish hooking up the jumper cables, the cop then pulls back up and just sits there watching us, and then when he sees me remove the jumper cables he just drives off again.
_Edit
There was another time that I was driving in my Versa a few weeks back on my way back to the college in the early afternoon. As I round a corner and approach an uphill stop sign, I see an old two-door VW Fox that obviously is a manual, and the driver can't get the thing going without stalling. I pull beside him, ask if he wants help getting it out of the stop sign. He refuses. I drive out of sight and wait to see if he makes it. Five minutes later, ten cars pass and none are him. So, I turn around, and he's in the same spot, still stalling out. This time I get out, walk right up and say "Hey man, want me to at least move it out of the stop sign? It will make getting going a lot less stressful." He agrees. I find out his problem. The old VW shifter slots very easily into third.
I get the thing out of the stop sign, explain what his problem was, show him the distinct feel of slotting the shifter into first. He gets in, and takes off just fine.