Achievement craft

Why is getting an achievement in video games so compelling? Is it that sense that "oh, shiny, I got something" or do we have some other drive that makes us want to accomplish seemingly meaningless tasks? yes, I could file my tax returns or I could beat fallout three on hardcore mode and earn fifty gamerscore, both witch take approximately the same amount of time.Why do I always chose the one that gives me a leading fifty points and barging rights among my friends? Is it that I see no real progress available to me from doing something real, when really this is the only thing that can offer me real progress? It's a mind bending question. So you know what I think? They should hand out achievements for doing your tax returns.