In case if you still doubted that the dolphins are forgetting their friends .which is including human and animals. It is not correct because they can remember and knowing their friends after 20 years .their brain are similar to human being as shown in the below picture
in the Recent research has shown that dolphins is calling each other by their signature whistles, similar to the way we address each other by name
Dolphins are not loving only to humans but also loving with animals as well. As you can see in the above picture.
See in the above picture.it is so amazing and charming.
Keep claim and swimming with dolphin