When we try to answer a question before we know how to, we will later remember the answer better, even if our attempt failed (Arnold and McDermott 2013). If we put effort into the attempt of retrieving information, we are much more likely to remember it in the long run, even if we fail to retrieve it without help in the end (Roediger and Karpicke 2006).
Trying to remember something and failing is better at creating memories than not trying at all.
