I’m not exactly sure how you do a grouch a favor other than leave them alone. If you do anything for them it will seem more like you have done something to them and they won’t appreciate it anyway. Once a Curmudgeon always a Curmudgeon! There will always be people ;like Scrooge and Archie Bunker, puppets like Oscar and whatever it is you call Moe of the Three Stooges. I think the answer is, live and let live. Grouch and let grouch. Just do it the best you are able.
How to celebrate – Find a Grouch and do them a favor. Remember if they like what you do they will probably no longer be a grouch. Could we have a Christmas Carol without Scrooge? No, I don’t think so!