There must definitely be something that attracts mossies to some, but not others.
Many years ago on holiday in Goa with a friend, I used to walk around in shorts , flip flops and t-shirt, and they hardly bit me. Even when they did, I just got a little non itchy red mark. Meanwhile my friend, who was sprayed up, wore long sleeved shirt, jeans and cowboy boots was getting driven mad. They were going up the jeans, down the boots and biting him through his socks, Large red spots on his ankles.
The worry there at the time was malaria, and we had taken prophylaxis.
They still don't bother me too much. Still a little red mark when bitten. But you only need to be bitten once by a carrier, and that is what happened to me about four years ago when I caught dengue. So I try to be more careful nowadays.