Although Indian monsoon mostly sets on in early June, it often deceives with vagaries of droughts or floods causing hardship to millions in the Indian subcontinent. It varies at the intra-monsoonal scale with 40-50 days cycle due to variability in the ITCZ/Hadley cell cloud formation an its migration towards Indian subcontinent. Due to numerous physical forcings interacting on monsoon at the same time, their linear/non-linear monsoon response has been mostly cyclic in nature in the last 12 million years. However, they are not yet fully understood and assimilated in predictive monsoon models with high reliability well in advance - at least at weekly level, so that farmers can plan their crops in better way. With such advance knowledge of monsoon, when it fails casting flood/drought, it makes us to realize that we do not know much for sure, that how would be the next monsoon within reasonable limits of the uncertainties