What's known as the "top knot" has a long ancient Asian history in Thai, Burmese, Indian, Korean, Japanese and Chinese cultures and each of these countries has its own word for it.
In China it is called a Ji or a Queue, in Japan it is known as a Chonmage, in Korea it is a Sangtu, in India the Joora, and in Thailand it it's called a Juke.
Of course, many foreigners do more of a hippy or feminine looking version of a pony tail with their hair long all over their head. But I assure you, if you shave the sides and back of your head down to around a half a centimeter, leave the rest of the hair straight and long just on the top, and then pull it back into a knot that extends about 2-3 inches just above the center of the scalp, then this appearance will help to gain you cultural acceptance in many Asian countries.
You may also find Thai men complimenting you on it in Thailand and many Thai women find it attractive in a masculine way if it is done in a neat and clean looking fashion.
Thus, regardless of age of the male bearer, the top knot hair style is timeless and admired by locals alike in many different Asian countries and cultures.