Can I start watching Reply 1994 without having watched Reply 1997 first? Is Reply 1994 like a continuation or related to some crucial points from the past drama, that you won't understand unless you watched it first? Or are they just two different dramas that have the same concept? Because I heard that there are cameos from the actors from the past drama, but I don't know. Can I? Or should I watch Reply 1997 first? xD Thank you!