Why am I 26 years old and my sister is still at work chatting with me and asking me my age? Am I immature?

Asking your age is polite, and the other person can't judge your age directly from your appearance. Even if you have a general understanding, you won't take it for granted. If a joke comes out one day, it will be embarrassing. Just ask your age politely, there will be misunderstandings every year.

This does not mean that you are immature. People mature through manners, not appearance and age.

Some people look very old or mature, but they are actually very young. Some people are young, or look like children, but they are smart.

Now in the company, there are 708090 or even zero, but many people are older than your information.