C++ rvalue references asssignment to lvalue reference

Question

Let's assume having:

template<typename T>
T&& f(T&& t) {
  return std::forward<T>(t);
}

Presenter p;

auto x = f(std::move(p));   // x is new Presenter object - move ctor invoked
auto x = f(p);                // x is new Presenter object - copy ctor invoked
auto& x = f(p);             // x is lvalueRef, no copy / move ctor invoked
auto&& x = f(p);       // x is lvalueRef, no copy /move ctor invoked
auto&& x = f(std::move(p));   // x is rvalueRef, no copy / move ctor invoked

and this is quite ok, hovever for that case:

auto& x = f(std::move(p));  // x is lvalueRef, no copy / move ctor invoked

Why we are able to assing to lvalueRef rvalueRef?

For instance we cant do:

auto& c = 1;

All help appreciated