Its not strange, its very common. Its called "bootstrapping".
> Bootstrapping is a fairly common practice when creating a programming language. Many compilers for many programming languages are bootstrapped, including compilers for ALGOL, BASIC, C, C#, Common Lisp, D, Eiffel, Elixir, Go, Haskell, Java, Modula-2, Nim, Oberon, OCaml, Pascal, PL/I, Python, Rust, Scala, Scheme, TypeScript, Vala, Zig and more.
> Bootstrapping is a fairly common practice when creating a programming language. Many compilers for many programming languages are bootstrapped, including compilers for ALGOL, BASIC, C, C#, Common Lisp, D, Eiffel, Elixir, Go, Haskell, Java, Modula-2, Nim, Oberon, OCaml, Pascal, PL/I, Python, Rust, Scala, Scheme, TypeScript, Vala, Zig and more.
https://en.wikipedia.org/wiki/Bootstrapping_(compilers)