My best friend is my ex

Is it weird that my best friend is one of my ex’s? We dated in 2016 and like a few months in 2017. I broke up with him because the last 3 months of that relationship just felt like a friendship. So after we broke up 4 months later i texted him and we just kept on texting and now he’s my best friend. We 100% do not have feelings for each other i just wished we could’ve just been friends from the start though.