own worst enemy, to be one's

be (one's) own worst enemy

To do things that complicate one's life and/or keep one from success; to be self-destructive or self-sabotaging. Of course Tommy started skipping school again—he's his own worst enemy. She always sabotages a relationship when it's going really well because she's her own worst enemy.
See also: enemy, own, worst
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

own worst enemy, to be one's

To be the major source of one’s own difficulties. The Greek philosopher Anacharsis (ca. 550 b.c.) already was stating this idea: “What is man’s chief enemy? Each is his own.” Cicero said it of Julius Caesar (Ad Atticum, 49 b.c.). In more recent times, cartoonist Walt Kelly expressed the same thought through his main character, Pogo: “We have met the enemy, and they is us.”
See also: own, to, worst
The Dictionary of Clichés by Christine Ammer Copyright © 2013 by Christine Ammer
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