How does changing your username affect mentions in old tweets?

When you change your username on platforms like Twitter, mentions in old tweets that were directed to your previous username can be affected in the following ways:

1. **Automatic Update**: On Twitter, when you change your username, the platform automatically updates mentions in old tweets to reflect your new username. This means that mentions that were originally directed to @oldusername will now display as @newusername.

2. **Linking and Accessibility**: Twitter ensures that mentions in old tweets remain linked and accessible after a username change. This helps maintain context and allows users to navigate to your profile through past interactions.

3. **Notification Updates**: If someone interacts with an old tweet where your username was mentioned, they will see the updated username when viewing the tweet. This ensures that notifications related to these mentions are correctly directed to your new username.

4. **Search and Discoverability**: Your new username will be indexed and searchable across Twitter. This allows users to find your profile and past interactions even if your username has been changed.

5. **Direct Messages**: Direct messages sent to your old username are not automatically redirected to your new username. Users need to manually address messages to your new username if they want to contact you directly after the change.

Overall, platforms like Twitter handle username changes smoothly to ensure that your profile remains connected and accessible across past interactions. This helps maintain continuity and ease of communication for both you and other users who have interacted with your account.