I wasn't attacking, Pittcity so you don't need those defenders! You wear what you want, and you looked great last December,so I am sure you always will.
Janerowena is almost right about the reason older people don't think much of mixing floaty summer cottons/ winter woollies. My reason is that in the 50s and 60s, when I was either at school or teaching, I saw a lot of children from hard-up families who had received cast-off clothes from charities.
Most of those seemed to be heavy jumpers that the previous owner had found too bulky, and thin dresses that had been worn for several summers already, or a once-worn fancy party dress. Many of the mothers who received these things had no idea of how to wash things effectively, or mend minor tears, so the poor kids would wear a draggled nylon frilly dress with a matted wool jumper over it. It advertised their status as "charity kids" - and it is the reason that people would rather be given money to buy new than accept other people's rubbish.