Unless someone enjoys this subject there's no reason they'd know about the different classifications. I read a lot about this stuff but still need to freshen up my knowledge every time I have a conversation about this for two reasons: the topic is too complex for an amateur and it also tends to be relatively fluid, changing based on new discoveries or theories. Always keep Wikipedia handy :).

If you ever look at different "artist's depiction" drawings about "dinosaurs" you might notice plenty of misconceptions: anatomically incorrect (and impossible) positions, strange mixes of species living in vastly different time periods, animals that aren't actually dinosaurs, etc.