<The church teaches, not at grade schools level, that one must follow one's conscience even if it is objectively wrong.>
Of course, you are absolutely right.  Ironically, that proposition was apparently taught more clearly and less ambiguously in the 1950s than it is today.  One result of the radically authoritarian papacies of John Paul II and Benedict XVI is confusion among putatively "conservative" or "traditional" Catholics about this basic fact of Catholic teaching.