“Nostalgia’ is a word very poetic. But, a person who is qualified to “Nostalgia”, must be old or going to be old. Young persons have nothing to nostalgia and middle-aged persons have no time to nostalgia.
But, actually, nostalgia is not to be recommended. Nostalgia means to remember the things of your past life. Whether your past life is of glory or disgrace, it is a history already. To remember is only to waste your life today. It is better to use your time today to enjoy your life, not to think about past which is actually of no use to you anymore.
Many old people like to talk things of their past to show that they had glory days when they were in the middle ages. Such conversations are entirely not necessary. What is gone is gone forever, no sense of talking any more.
We must keep our life in young attitude even we are old. The secret is never to talk about past. Besides, if you are old, with experience, people of younger generation will come more often to ask your advice when problems fall upon them. Therefore, you can only give your idea upon request. Do not be a teacher by you voluntarily.