Im a yr of a sheep and my best friend a yr of a monkey we are best friends are we going to last?

Well, me and my best friend Bryan have been through fights and ups and downs however, we always forgive and forget we never stop our trust or love for each other. We have mostly the same personality and traits. But one question, is our relationship going to last? Because our relationship has been going on for 4 yrs at least. Also I'm best friends with a sheep and a monkey are our relationship going to last? That's my question.