2. The greatest source of misery and hatred in this world is clinging to past hurts.
这个世界上痛苦与仇恨最大源泉是对过去的执迷。

Look at all the terrorists and militant groups that hark back to some event long gone, or base their justification for killing on claims of some supposed historical right to a bit of land, or redress for a wrong done hundreds of years ago.
看看那些恐怖组织和激进分子，他们总是抓住过去的一些事情不放，或把一小片土地的历史归属问题作为他们进行杀戮的理由，更或是为了修正几百年前的所谓的历史错误。