Am I being unintentionally selfish?

Once every couple weeks I have to go to our main office to pick up supplies. Sometimes the stuff is not that heavy but other times the boxes are a bit big and are at least awkward to carry if not heavy. The guy that orders the stuff for the different programs always makes a point of helping me carry the stuff out to my car, including helping me put it in my car. I notice for the other programs however that their stuff is left back by the back door and they pick it up themselves. Now I know it would be a bit of a struggle if I had to carry my stuff out myself but I could make do if I had to, so my question is, am I being selfish in taking this person’s time? Should I just try and do it myself like everybody else does?