One of my selfless acts of general kindness is to pick up my walking pace to beat the older or otherwise less mobile, maybe hands full person near me and hold the door open for that same person, no matter where or what the weather. Often I will get the "you don't have to hold... i simply reply "i'm in no rush, let me do this for you".

Truth is I may be running a tad late but screw it, maybe I am, so I can be there at that moment.