People have the right to privacy, but there is no reason why a person must have privacy if they choose to not guard their privacy. Many people decide they want to share details about themselves, including personal experiences for social interaction and other reasons. It is very normal to do this.

Similar to privacy, people can talk about, including ask about, anything they want. If you have something you want to keep private, some people may look for clues about this private information, and some people may inquire about this private information. If you want this information to remain private, you should not leave any clues, and you should share this information with those you are sure you can trust not to further share it.

If you are posting about where you went one summer, or other personally-identifying information, you should expect people to know about it, even if you try to delete it from the internet. You should expect anything you post online to remain forever.