What condition must exist to make a demand curve accurate

as long as ceteris paribus consumption is true

Explanation:

Ceteris paribus refers to the the assumption that 'other things remain equal". For example, generally it is safe to assume that demand for a certain product will Decrease if the price of the product is increased.

But that situation can only be guaranteed if other factors beside the product and the price remain equal. Exemption of this would be when the country is in a crisis and demanded product become rare, it is very much possible that the demand will keep increasing even if the price keep skyrocketing.