Threads like that one kept me from riding with anyone except family for a good while. Finally I was convinced to try our local group. I showed up riding a hybrid with sketcher shoes regular shorts & a t-shirt. Another first timer (a young lady) was on a mountain bike dressed about the same. All the regulars had full kits and road bikes. No one laughed (at least not out loud) and away we went. I stayed at the back and a couple of fast riders took off doing their own thing. I found I could keep up and was soon riding along visiting with a nice looking lady 2/3 my age. One couple dropped back to make sure the girl on the mountain bike could keep up and was having a good time. The ride was over way too soon! Now I ride with some of them at least a couple times a week. I have found one lady who is close to my age and we ride about the same pace. She has talked me into doing 3 events and we are doing another tomorrow, my first metric century. I would have never done a event if I hadn't met them.
The moral of this story is all groups are not the same so don't short change your self because of threads on here!