Many times, the portraits of celebrities in textbooks are portraits of the elderly. Young portraits are rare. In addition to the above reasons, it may be that the celebrity did not leave a portrait when he was young. People in the past were different from people now, and their technology was underdeveloped, so it was difficult to preserve portraits. Even if a portrait is painted, it is difficult to preserve. Many famous people in history may not be able to leave portraits. You know, these celebrities are famous enough in their later years, and some people left no portraits in their later years, let alone when they were young.
And few people become famous when they are young, unless you are a genius. Not a genius or a celebrity, even if there is a portrait, it will not be thrown away as a piece of waste paper. The chances of staying are very low. Like many poets, the records they can leave are particularly important historical records and world masterpieces. Therefore, future generations must rely on these records to restore the appearance of celebrities. These are the situations in the East, and the celebrities in the West may be slightly different. Portraits of western celebrities are quite common, but not everyone has their own portraits when they were young.
Generally speaking, the portrait in the book is to let future generations know this celebrity and remember his achievements. Of course, when he achieved the most outstanding achievements, he would choose more portraits. When did he achieve his most outstanding achievement? Then you get old. Except those who are famous in their early years and have no news, or who die young, they will choose more portraits of old people.