Mark Poore's comments about looking in the mirror remind me of a bit of a faux-pas I commited a few years ago in a local bike shop. This shop specializes in the latest "boy-racer" bikes and sponsors a fairly decent local team but has no vintage stuff.
I was in the shop buying something and overheard a customer standing next to me talking to the sales guy. The sales guy was pushing some ultra lightweight component that cost several hundred dollars to the customer and emphasizing the fact that the purchase would save an unknown number of grams over what he was currently using.
The customer, who stood over 6 feet, weighed at least 225+ with a typical middle age bulge, turns to me and asks for my thoughts on the issue. After giving him a good look from head to toe, I tell him that he could skip lunch for a few days and realize the same weight savings at no cost -- in fact it would put money in his pocket!!
At this point, the sales guy asks me to leave since I was disrupting his business. Not wanting to make a scene, the customer and I both walked out together laughing at which point he thanked me.