After making a successful debut with "OK" in April, B1A4 has begun their follow-up promotions on today's MBC Music Core with "Only Learned the Bad Things". Written by Wheesung, the song is about a man trying to win back the feelings of a lover who's already turned her back on him due to his past mistakes. The members said, "We're extremely grateful that Wheesung took the time to write for rookies like us. We feel that it's an honor to be able to promote with his song, and we promise to show our best in consideration of the people who have worked so hard for us." Check out their follow-up stage below!