The knowledge of masculinity has developed rapidly in the past 20 years, and male knowledge has also improved. Due to the influence of feudal consciousness in the past, as well as the influence of traditional culture, religious beliefs and other factors, there are more common mistakes in the understanding of sex, the common ones are: (1) “a drop of semen is equal to ten drops of blood”, ” Ejaculation will be greatly injured”, the normal semen ejaculation, considered harmful to the body. In fact, ejaculation is a normal physiological phenomenon, not only will not be greatly injured, but also beneficial to health. This misconception brings a huge burden to the man’s spirit, and over time fear arises, causing sexual dysfunction such as non-ejaculation or retrograde ejaculation. (2) penis size and orgasm equals some men often think their penis “small”, will affect the sex life, the general penis 7 to 10 cm long, in the penis after full erection, more than 1 times the growth, and the small penis erection increase ratio is certainly much larger than the large penis erection increase ratio, penis size will not affect orgasm. (3) do not pay attention to the sexual rights of the elderly With the improvement of people’s standard of living, life seventy is not strange, the elderly society is coming, the quality of life of the elderly is concerned. Now some people think that sex is a matter of young people, if the elderly have a normal sex life, there is an incorrect view, especially the elderly widowed, remarried, but also that the old is not “dead”.