Answer: Metaphorically, it could also mean that someone has focused on attack rather than defense, or that they are willing to go on the offensive but are not prepared to defend themselves.
Explanation: The phrase "They took the spear but left the shield" can be interpreted in various ways depending on the context. Generally, it can mean that someone has taken an offensive weapon (the spear) but has left behind a defensive one (the shield). This could imply that someone is willing to take risks and be aggressive, but is not adequately prepared to protect themselves from potential harm. It could also imply a situation where someone has gained something but has left behind something equally valuable, or has made a trade-off that is not entirely advantageous.