There are many expressions commonly used in English to express similarity.
There is no magic rule to help you remember them. You just have to learn them. Sorry!
Take a look at the examples below.
(To be) like a dog with a bone.
This is used when describing someone who is fixated on a particular problem or topic. The person is determined to continue and is unwilling to stop (talking about it) until the problem is dealt with or a solution is found.
E.g. As a journalist if she senses it’s a good story, she won’t let it go. She’s very determined – like a dog with a bone.
(To be) like a fish out of water.
This is used when someone is feeling out of place or uncomfortable in a new environment or with new people.
E.g. I had lived in big cities for my whole life. When I retired and went to live in the countryside I felt like fish out of water at the beginning. I had to get used to my new way of life. Now I love it!
Have fun learning English!
Louise