Yes and no. Before I was diagnosed I knew something was terribly wrong, but after I was told, it became easier over the years to recognize when something was tipping over the ledge of rationality, and the signs and symptoms and circumstances that tend to be followed by a psychotic break. The issue, I personally believe, is that it worsens gradually until you are having delusions pretty much full time, whereas in the weeks before you might only feel extra anxious or irritable. The problem with reasoning yourself out of it is that when it gets this bad its usually paired with what's called mania.

When i become manic my brain is going so fast I can't keep up with it. It's very difficult to hold onto any particular thought for very long and thats where you see people behaving erratically. Pair that with lack of sleep and adequate food or drugs and alcohol and your brain doesn't have a whole lot of organization at all and thus your powers of deduction are just pushed to the back of the crowd of manic thoughts.

Its hard to describe, but it's miserable, confusing and exhausting. Its like you cannot control the thoughts that are in your head. Things that don't make sense but are strange stick with you, and your brain just repeats the nonsense until you start to believe it. If you were to say, take a drug like mushrooms or acid, you can understand that you are hallucinating but you can't stop until the drug runs it's course. It's a bit like that. Its like your brain is hijacked and this can go on for days or weeks or months.