_Not_ recalling an ad doesn't mean that it isn't actually in your brain. Professor Robert Cialdini sited research in his book "Pre-Suasion" that the most effective ads were those that were _not_ recalled by users. You're effected by ads more than you think or recall.
https://www.amazon.com/Never-Split-Difference-Negotiating-De...
https://www.amazon.com/Effective-Negotiating-Strategies-Succ...
https://www.amazon.com/Pre-Suasion-Revolutionary-Way-Influen...