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
Ximo	-	Catalan, Spanish
Cynebald	-	Anglo-Saxon
Thiemo	-	German, Dutch, Ancient Germanic
Vadim	vah-DEEM	Russian
Pejo	-	Croatian, Serbian
Artemios	-	Ancient Greek