It was kind of painful for me to read this. There are so many reasons someone might not deeply engage in a conversation, and it can feel hurtful, but it's usually not because they are trying to be rude.
They might have had something on their mind, had a bad day at work, didn't want to be at the social event, whatever.
They might have had something on their mind, had a bad day at work, didn't want to be at the social event, whatever.