The patterns of behavior frequently exhibited by (usually) young people who have recently come out, guided by a thirst to discover a world containing homosexuality and other homosexuals than themselves, which may strongly contrast to the heteronormative world they grew up in. Common behaviors include reading gay literature or watching gay films, using Wikipedia to memorize the names of all gay celebrities, or joining a gay club or group to meet friends or potential lovers. An occasional related behavior is the consumption of slash fanfiction.
When I had New Gay Syndrome, I read a bunch of lesbian romance novels. Glad I got that out of my system!