If get married young, you both take good care of your health, avoid dangerous activities, and God grants you both a long life, and if you don't get a divorce, you should have a relatively long-lasting marriage.
If you want the marriage to feel like it lasts a long time, you could engage your partner in conversation and spend hours every night discussing everything about your partner that could be considered a fault. That might actual shorten your partner's life span, and therefore, the duration of the marriage, but it will feel like it lasts a long time.