Direct Opposites:
* Ignore: To pay no attention to something.
* Dismiss: To reject or disregard something.
* Overlook: To fail to notice something.
Words Suggesting Quick Action:
* Rush: To do something quickly or without thinking.
* Act impulsively: To act without considering the consequences.
* Decide immediately: To make a decision without hesitation.
Words Suggesting Lack of Thought:
* Neglect: To fail to pay attention to something.
* Forget: To fail to remember something.
* Disregard: To pay no attention to something.
The best antonym for "ponder" will depend on the specific context in which the word is used.