Why learn to identify rāgams
Here is a great article by Arunk that talks about the thrill of finding a rāgam, and being on cloud nine, followed by an insightful comment thread. Beyond that thrill and excitement (which for me has never gone away in decades), as a poster in the comment thread says, one needs to identify rāgams reasonably quickly for this reason:
because the alapanam needs to be listened to in the context of the ragam by a reasonably competent listener.
Enjoyment of a piece, including the manodharmam aspects (ālāpanai, tānam, kalpanāsvaram, neraval) undergoes a drastic increase after the point one has identified the rāgam, and can relate to it via its aspects in in one’s mental database, including the beauty of its grammar, phrases, bhāvam, feeling, and more.
Listening to a piece without having identified its rāgam is like engaging in a conversation with an old, good friend you ran across, without quite having identified who they are. There is something fundamental missing in that interaction. Perhaps one can discuss the weather, but the conversation is devoid of depth and enjoyment without context. Identifying the friend brings in a flood of context—memories, stories, and such—and takes the conversation to a whole different level. (On a tangential note, learning a new rāgam is like making a new friend!)
And so, learning to identify rāgams is arguably the foremost skill to learn for an aspiring rasikā.