Have no recollection of that game. I would assume most people would assume (as I did) that Essien had played against us fro Chelsea while Keane was with us. Not sure they did but, either way, Keane was going downhill and most likely was in that Lyon game you refer to as well.
Essien was without a shadow of a doubt the player we most envied Chelsea having. Not Drogba, Robben, Lampard, Makelele, Terry, Carvalho, Cole... Essien. That in itself says a lot, and not just that we needed someone exactly like him.
But you do realise that if you have to refresh people's memories about something that happened 8 years ago, you have the same issue with Blanc and Rui Costa (I loved the Fiorentina Rui Costa, for example, more so than the Milan one). The age of the RC population is relevant, bugger all you can do about that.
Even Henry's popularity in these drafts has changed dramatically in the last few years. Cristiano had already done everything he did in the EPL and Henry was still considered a bigger EPL great, then the Messi-CR 1gpg generation started to kick in and suddenly Henry is no better than Benzema.