Jim Courier did have a great forehand and it's not talked about as much as it should be perhaps. But what about longevity? Why did Courier's game decline so badly?
Similar thing happened to Roddick in terms of his forehand, it was considered a weapon in the early 2000s and for the last four years or so, everyone says his forehand has no sting, he's tried to put too much spin, he's way too behind the baseline etc.
Courier did an interesting interview in Tennis magazine in 2000 when he retired, I haven't seen it since then but I remember some of it well (including his reluctance to talk about his girlfriends but the media will probe anyway). The interviewer asked him about that and Courier said he heard the theories about it losing its sting because of those matches with Sampras. If you remember, Courier attacked Sampras' backhand constantly and relentlessly with inside out forehands over and over again but Sampras resisted and came out on top in 3 quarters of their matches. I suppose the theory was that Courier lost heart and his form after so many losses in big matches including Roland Garros.
This is an interesting example of what I'm talking about.