I agree fans shouldn't be arguing with children / teenagers but I also don't think that being over 30 or even over 25 etc means you should stop taking part in fan activities - any more than any other hobby. Can be generalised to: UO - we're living longer than ever, people should mind their own business and stop moralising about "35-40 is middle aged and by this age at the latest, preferably by 30, you should act like other people's idea of grown up even if it means doing things you don't want to do or stopping doing things you like"
We've had discussion about fat activism before but I think it's especially grating when people have this mentality even when they can physically see it isn't true. I know a woman who had diabetes during pregnancy so her doctor put her on a strict diet and she lost a lot of weight - she was considerably slimmer after giving birth than before she got pregnant (all with medical supervision, the baby was fine.) She commented "well it's just temporary, I 'won't keep this thinner body' (exact quote), my ~set point~ will take me back to being very obese." More than a year after she gave birth, she hasn't put the weight back on, why? She's still following the diet at doctor's request because having had diabetes during pregnancy puts her at higher risk of Type 2, and she's a lot more active now that she has a young child to run around after. Yet still believes that diet and physical activity have nothing to do with weight loss! Similarly there was a well known "fat activist" who constantly claimed it was physically impossible for her to lose weight, but then she lost weight after a change of medication and didn't put it back on