I know I would.. Jumped into many situations in the past without thinking first. I just would.
As a teen, came across a man actually strangling another semi concious man on the floor.. jumped on his back.. saved man!
Bit older.. driving along, came across cottage on fire in countryside.. flames shooting out the chimney.. ran into smoke filled room and pulled old bloke out who was overcome by smoke.
bit older still.. walking down the highstreet carrying my shopping.. a madman had pulled a knife on this other bloke.. dropped shopping and jumped on madmans back.
Walking the dog late at night.. saved a bloke from a sever beating by knocking assailant out. He was massive too!
There are many more..
Frankly.. I'm just fking stupid.