"Si una mujer te dice que tiene veinte años y parece tener dieciséis, tiene doce. Si te dice que tiene veintiséis y parece tener veintiséis, está malditamente cerca de los cuarenta."

Simplified Meaning:

Sometimes, when people talk about their age, they might not be completely honest. For example, if a young woman says she is 20 years old but actually looks much younger, like 16, she might really be even younger, like 12. On the other hand, if a woman says she is 26 and she indeed looks exactly 26, she could actually be a lot older, maybe around 40. This can happen because people often want to appear younger or older depending on how they feel about their age. In real life, think about people using filters or makeup to look different in photos. They might present themselves in a way that doesn't match their true age. The advice here is to be aware that people’s appearance and the age they claim to be aren't always accurate. So, use both what you see and what you hear, but keep in mind there might be more to the story. This can help you make better judgments about people and situations.