Folksonomy, tag, bookmark and social bookmarking are all concepts that refer to recollection in information retrieval (IR). Recollection can be defined as the effort needed to recall an even, an idea or a resource. In IR, when locating an interesting resource, a user can tag it in order to "memorize" it and retrieve it later. The user chooses the tags according to his/her needs or centers of interest. While previous work has addressed the problem of tag exploitation, to our knowledge, an important dimension is missing. None has focused on the tagging activity itself when considering the users point of view. An important open question is the following: will a user be able to remember tags he/she associated with a document in the past in order to retrieve a document again? Our paper tackles this problem. Considering a user study that implied 32 participants, we evaluate some elements (age, time...) that impacts the recognition and the recall of tags used in the past. This result is important specifically as it can be used in order to optimize personalized systems (e.g. user profiling, tag exploitation...).