Adequate reflection of real time in man's mind is a necessary pre-condition of his efficient adaptation to the ever changing environment. Differential-psychological peculiarities and maturity of notions of "present, past, and future; quick and slow", as well as the ability to correlate other people and things with one's subjective time, and one's emotional attitude - to the speed of reactions in others, - are connected not only with development of the perceptual sphere, but with the conceptual-intellectual, emotional, and volitional development of one's personality as of a subject of cognition.