Anterograde amnesia is a condition in which individuals are unable to create new memories from experiences. The most identifiable case of this type of amnesia in film comes from the movie Memento where the main character even tattoos messages to his body in an attempt to remind himself of events taking place after the amnesia.
A more playful and lighthearted portrayal of anterograde amnesia can be found in the animated film Finding Nemo. Although the amnesia is not specifically referred to, one of the main characters is a fish called Dory who can't remember anything for more than a few seconds and cannot make new memories which suggests anterograde amnesia. Throughout the movie Dory is always getting lost and frustrating her companions, but amnesia can be a much more dangerous in real life situations and should not be made fun of. Here's a short clip from Finding Nemo: