Actually I do, cause it’s a collection of objects and I want to mutate the variables of the object
Getting to know the difference between mut and other types are very important in the beginning as this concept can be found in multiple places such as iter() and iter_mut() and into_iter(), as well as get() and get_mut(). One nice periodic table for rust types The Periodic Table of Rust Types
Having heard the mention of word object quite a few times, I would say that getting to think from a data point of view is very important in rust, which might be a bit different as compared to thinking from an object perspective. Rust Koans - #2 by DanielKeep describes this nicely in story form.