How long is the normal love time in psychology?

Psychology is neither prediction nor fortune-telling, so it doesn't say how long normal love lasts. But usually know a person completely, it is best to be in love for not less than 3 years. The first year, because it is a love period, the second year is an understanding period, and the third year is a stable period. Therefore, once the stationary period has passed, the cumulative number of meetings will not be less than 1000 in these three years. Then it is effective. If it is a long-distance relationship, it is only once a week. It is impossible to get tired of pretending to be innocent and gentlemen. Because if we only meet once a week, we will only meet four times a month and 48 times a year. What can you learn about each other in just 48 times?