That awkward moment when you wave hi to someone and they don't wave back, you pretend to play with your hair

This situation once happened to me, so I was in the 4th floor hallway at my school, when my friend waved hi to me and I waved back like a maniac, and she looked at me weirdly and the person in back of me goes to hug her, I figured out that it wasn't directed to me and I pretended to play with my hair. Take my advice, don't wave back if they are not looking directly at you *_* hehe *sweatdrop*