Attachment.

Yes. I’ve been reminded for not depending my happiness on other people. They might have lifted me up at one time, but at the next moment, the person who I trust, who can make me happy when I’m down, may leave me & disappoint me.

Try not to put a high expectation on any person who is close to you right now. Cause somehow someday she/he will leave you (with or without some reasons), and at that very moment, you will be confused and don’t have anywhere to cling yourself to.

The point is, try to let yourself be happy by depending on Allah SWT. Most attachment leads to disappoinment except attachment to Allah.