Trying to pattern match in Elixir, variable to variable

elixir_test.exs

pattern   = %{foo: "bar", bar: %{baz: "qux"}}
good_data = %{foo: "bar", bar: %{baz: "qux", qux: "asdf"}}
bad_data  = %{foo: "baz", bar: %{baz: "asdf"}}

### This is perfect
match?(%{foo: "bar", bar: %{baz: "qux"}}, good_data)
#=> true

match?(%{foo: "bar", bar: %{baz: "qux"}}, bad_data)
#=> false

### Can I replicate it with a variable?
match?(pattern, bad_data)
#=> true
# Matches bad_data?

match?(pattern, good_data)
#=> true

# Pinning
match?(^pattern, good_data)
#=> false
# Doesn't match good_data?

match?(^pattern, bad_data)
#=> false

# Does anything work with the pinned variable?
match?(^pattern, pattern)
#=> true
# Apparently exact matches

# Let's try a case
case good_data do
  pattern -> true
  _ -> false
end
#=> true

case bad_data do
  pattern -> true
  _ -> false
end
#=> true

case good_data do
  ^pattern -> true
  _ -> false
end
#=> false

# Same freaking problems as above

# Do raw maps work in function definitions?
defmodule Test do
  def match_me(%{foo: "bar", bar: %{baz: "qux"}}) do
    true
  end
  def match_me(_) do
    false
  end
end

Test.match_me(good_data)
#=> true
Test.match_me(bad_data)
#=> false

# Got that going for us, anyways