Some do, some don't. There's really no certainties with the condition as it is, well, quit odd.
From what I've gathered (and I'm no expert) the majority of people developing schizophrenia don't realise anything's wrong with them, since the part of the brain responsible for self-analysis often breaks down.
To be honest, Tau, there's no way to guarantee that you won't get it...there will always be the exception to the rule which you can look at to make yourself "fit" the case. You just have to learn not to care anymore.
I've pretty much come round to the idea that I might be developing it now, but I really can't be bothered to worry about it anymore.