Giving Gasoline and "PIF"

I figured I'd write you with my own type of PIF that was directed at me. I ride a motorcycle and I know relatively to the mile when I need to get gas.  Well this morning I pushed it too far, I was not too far from a gas station but far enough that it would of been a pain to push the bike to the station.  When it happened I only could blame myself.  I pushed it into a neighborhood and I guess someone getting ready for work saw me and came out saying he had a gas can he would let me use, I thought sweet that way I won't have to buy one.  When he brought it out and handed it to me it was full, it caught me off guard and I didn't know what to say, all I needed was a few ounces to save me a bunch of time.  

I'm really independent and I have never really been in a situation where I was the one that needed help but I was very greatful for the guy going out of his way to make my life a lot easier when he could of just ignored the whole situation.  I didn't know how to thank him other then just to say thank you, and to continue to "pay it forward"