The RER B is my go to method of travel to/from CDG for several reasons.
First, it seems more French than buses or taxis (make no mistake, the French taxis are sufficiently Gallic and with a larger group, they make a lot of sense) and I am immediately immersed in the French culture, what with advertisements and announcements on the train.
Second, the trains are an adventure. Even in my sleep deprived state after landing at CDG, I feel as if I am rising to a challenge on my first day abroad. It FEELS like I am really traveling.
Third, I like the sense of mild anxiety that I feel when I am trying to plan and travel from my hotel or apartment in central Paris to arrive safely (and early enough) for my transatlantic flight. I like that feeling of controlled panic and that sense of uncertainty.
On my last trip home from Paris, I was staying in a sub par VRBO apartment in the 10th. My significant other and I had arrived back in Paris on the TGV from Nimes. Although I am averse to purchasing a lot of souvenirs, she is not an adherent of my lean and mean travel method, so she purchases gifts liberally, reasoning that we can mail them home from Mailboxes, Etc., which we have done in the past. In Barcelona, we searched in vain for an open branch of that transport company, and finally became resolved to carrying them home in a wheeled suitcase that we would check. I purchased the largest wheeled suitcase I thought I could handle.
So, there we were at 5:30 a.m., walking from our apartment in the darkness along rain slick streets to the entrance of the Gare du Nord, where we descended into the underground complex toward the RER station.
Did I mention that I had broken my left wrist about two weeks earlier in Nice? I was essentially one handed, my carryon on my back, and my personal bag crossed over my chest, as I pushed the world's heaviest roller bag full of "stuff" to the station. In what can only be described as waves of purest joy washing over me, we clunked down the steps into the Gare du Nord station, and into the RER station. The descent into the track area was uneventful, and when the RER B approached for CDG, I knew I had become a Parisian. I love the RER.