They call it "The Joy of Learning After 55," and there's proof in the packaging. Seniors who never thought they would darken another classroom door are registering for lecture series on everything from "Opera for Dummies" to computer classes, "Shakespeare on Film" to pottery, photography and estate preservation. For fees that range from $10 to $20, there's something for everyone. And for those 65 and over, the fees are waived. For up-to-date information on the program's offerings, access www.rlc.dcccd.edu/emeritus.htm.