One interesting outcome of widespread internet access is that you have young and older people mingling on a regular basis outside of the usual hierarchical context (e.g. parent-child, teacher-student, employer-employee). If I were living 30 years ago, there is absolutely no way I would be well-versed in the equivalent of zoomer slang (I guess it'd be Gen X slang?), but since we occupy the same spaces it's natural for that kind of linguistic exchange to occur. Since it's only a relatively superficial exchange, I don't think most of us geezers can appreciate all the underlying complexity to be able to use and comprehend the slang at a "native" level, but it prevents us from being left completely in the dark.