I have felt the same in public....like I need to justify what's in the bottle!! When I want to heat it up and ask for hot water they ask why they can't put it in the microwave? Cos You Will Kill All the Goodness you idiot I feel like shouting!!!
It will be a never ending battle but I'm not one to worry about what other people think!!! It was frustrating tho!!!! I also had the problem of people looking at me funny cos I used a special needs feeder( due to the cleft lip) It has a strange fat/long looking teat!!! Double the strange looks!!!