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.

Common Names:

Name	Pronounced	Usage
Pollyanna	pahl-ee-AN-ə (English)	Literature
Gonca	-	Turkish
Dorit (2)	-	Danish
Charis	['tʃæris]
Zhihao	-	Chinese
Rosy	ROZ-ee	English