Confusing syntax of self

help
1

I find myself constantly thinking if I should prepend self with ampersand or not, and I'm surprised it is sometimes a reference and sometimes not, depending on the signature:

fn this(&self) -> &Self {
  self // why not &self
}

Looks like self is not always of type Self, but its type depends on the signature. Yet this is inconsistent with how pattern matching syntax or closure parameters work:

vec![1, 2, 3].into_iter().filter(|&num| num > 0) // here `num` is *not* a reference

I wonder - do other people also find it confusing?
Is there a reason it was designed that way?

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