We are all naive about some things, inevitably. If we are wise, we know when we are naive, when we are stupid we are unaware of our naivety and act as if we understand a situation. A recent experience of mine: my wife and I have been to the US on a holiday. We spent some time in different cities (Seattle, Vancouver, San Francisco, Brooklyn/NYC); now each city’s public transport city operated in a slightly different way. Tickets, free areas in some cases, how to pay, etc: we had to inform ourselves and understand the system if we were to minimise the cost and get to where we wanted to get. On arrival in each city, we were ‘naive’, inexperienced. Had we assumed the system would operate the same way as London Transport, we would have been ‘stupid’.
Oxford Dictionary of English: naive: adjective, showing a lack of experience, wisdom, or judgement: the rather naive young man had been totally misled.
A patient of mine who had moved to Clapham and could not see why he needed a local GP: he was unaware that GPs visit their patients if they are too unwell to get to the surgery. In this sense, I would say he was naive, he simply was unaware of how the system works. He was sensible enough to see that there was no way that I would trek across London to visit his sick bed.
the rather naive young man had been totally misled: this sentence brings up the other side of the coin. People can be naive through lack of experience, but this lack of experience can be taken advantage of by others. In this case, I think it is clear that the Department of Health are misleading people and taking advantage of their naivety. I will offer some concrete examples later.