Storing something in response to an explicit user request seems fine without additional consent, though you still need to explain to users how the cookies are used to fulfill their request. [1]
On the other hand, there are many things that sites do that are not fully explicit. For example, shopping sites often show you items you have recently viewed to facilitate comparisons, or a news site showing ads might want to make sure they don't show you the same one over and over. That doesn't sound to me like it is strictly necessary for the functioning of the site?
[1] "users are provided with clear and precise information in accordance with Directive 95/46/EC about the purposes of cookies or similar devices so as to ensure that users are made aware of information being placed on the terminal equipment they are using"
Couldn't sites wait to ask for cookie permission until the actually user tries to do something that may benefit from a cookie? Like put text and a link with an explanation next to buttons to change the theme or regions which may contain recently viewed items.
On the other hand, there are many things that sites do that are not fully explicit. For example, shopping sites often show you items you have recently viewed to facilitate comparisons, or a news site showing ads might want to make sure they don't show you the same one over and over. That doesn't sound to me like it is strictly necessary for the functioning of the site?
[1] "users are provided with clear and precise information in accordance with Directive 95/46/EC about the purposes of cookies or similar devices so as to ensure that users are made aware of information being placed on the terminal equipment they are using"