According to the author of 2 Chronicles, Amon was a young man, 22 years old, when he became king and he was king for only two years in Jerusalem. From a Christian point of view, this shows that even though he was young, Amon had a big responsibility leading the people but didn't get to do it for very long.
2 Chronicles 33:21: Amon [was] two and twenty years old when he began to reign, and reigned two years in Jerusalem.
This verse states that Amon was twenty-two years old when he began to reign, but 2 Chronicles 33:21 may conflict in other detailed accounts of Amon's reign.
2 Kings 21:19: Amon [was] twenty and two years old when he began to reign, and he reigned two years in Jerusalem. And his mother's name [was] Meshullemeth, the daughter of Haruz of Jotbah.