Someone told me schizophrenia can strike suddenly, is this true? i thought it was something that developed over months/years not instant delusions?

Sudden does not mean: overnight. Schizophrenia often appears in young adults, e.g., college and military age. Subtle signs in affect or thinking may appear months before it is diagnosed. If you have concerns please see a mental health professional. There are different types and degrees of this illness and many folks function very well w/it. Peace and good health.