This video says about itself:
Rescued octopus came back to thank us
2 December 2014
We spent our holidays at the Red Sea. While walking along a lonely beach we saw a stranded octopus in the sand. We were not sure if he was already dead. So we pushed him back into the water. He needed some minutes to recover, then he swam away.
Next day we went to the same beach for a walk. While walking along the beach we saw a shadow in the water coming very quickly to us. It was our octopus we rescued yesterday! He recognized us! He accompanied us for a long time while we walked along the beach, all the time he tried to touch our feet.
We are sure that this octopus came back to thank us for saving his life. It’s amazing how intelligent animals are.