What about properly learning one you already started? And @Angry_Panda I think you meant Kobold. Pretty similar, but Cobol won't save you in a D&D game.
@Manko-sensei - no, but it will keep you in work for the foreseeable future. Leading up to 2000, a bunch of businesses and US government agencies were thinking about getting off of COBOL systems to something more modern. Many are still thinking about it.