The 12 months are like the 12 sons of Yaqub. Just as Yusuf (as) was the most beloved son to Yaqub (as), Ramadan is the most beloved month to Allah. Just as Allah forgave 11 brothers through the dua (supplication) of 1 (Yusuf), He forgives 11 months with the duas of 1 (Ramadan).
Ibn Aljawzi (via Twitter, Dr. Omar Suleiman)