My ever-observant colleague, Lee Hollingdale, pointed out - quite fairly - that my claimed disdain for the National Lottery is inconsistent with my membership of a syndicate.
My grasp of economics (or maybe psychology) is insufficient to clearly explain what's going on here but I'll do my best.... I participate in the team syndicate because I'd hate it if I left and they won. So I guess the potential cost I perceive of missing out on a big win when others I know have not is greater than the money it costs me to participate. I'm not sure how rational that is but Lee... I'm going to continue playing!