diff --git a/README.md b/README.md
index 013a777..6369f32 100644
--- a/README.md
+++ b/README.md
@@ -138,6 +138,12 @@ enum BackedEnum: int
 
 The above enum defines 3 meta for each case: `color`, `shape` and `isOdd`. The `#[Meta]` attributes are ideal to declare static information, whilst public non-static methods are ideal to declare dynamic information.
 
+To access a case meta, we can simply call the method having the same name of the wanted meta:
+
+```php
+BackedEnum::Two->color(); // green
+```
+
 `#[Meta]` attributes can also be attached to the enum itself to provide default values when a case does not declare its own meta values:
 
 ```php
diff --git a/src/CasesCollection.php b/src/CasesCollection.php
index c74686c..a7a0e28 100644
--- a/src/CasesCollection.php
+++ b/src/CasesCollection.php
@@ -112,10 +112,10 @@ public function toArray(): array
     /**
      * Retrieve the first case.
      *
-     * @param (callable(TValue, array-key): bool)|null $callback
+     * @param ?callable(TValue, array-key): bool $callback
      * @return ?TValue
      */
-    public function first(callable|null $callback = null): mixed
+    public function first(?callable $callback = null): mixed
     {
         $callback ??= fn() => true;
 
diff --git a/src/Concerns/CollectsCases.php b/src/Concerns/CollectsCases.php
index 8e1e9aa..9944313 100644
--- a/src/Concerns/CollectsCases.php
+++ b/src/Concerns/CollectsCases.php
@@ -30,9 +30,9 @@ public static function count(): int
     /**
      * Retrieve the first case.
      *
-     * @param (callable(self, array-key): bool)|null $callback
+     * @param ?callable(self, array-key): bool $callback
      */
-    public static function first(callable|null $callback = null): ?self
+    public static function first(?callable $callback = null): ?self
     {
         return self::collect()->first($callback);
     }
diff --git a/src/Concerns/SelfAware.php b/src/Concerns/SelfAware.php
index 2527f22..9953132 100644
--- a/src/Concerns/SelfAware.php
+++ b/src/Concerns/SelfAware.php
@@ -147,7 +147,7 @@ public function resolveMetaAttribute(string $meta): mixed
             }
         }
 
-        throw new ValueError(sprintf('"%s" is not a valid meta for enum "%s"', $meta, self::class));
+        throw new ValueError(sprintf('The case %s::%s has no "%s" meta set', self::class, $this->name, $meta));
     }
 
     /**
diff --git a/tests/BackedEnumTest.php b/tests/BackedEnumTest.php
index e880fe8..67e5b17 100644
--- a/tests/BackedEnumTest.php
+++ b/tests/BackedEnumTest.php
@@ -394,7 +394,7 @@
 });
 
 it('handles the call to an inaccessible case method', fn() => BackedEnum::one->unknownMethod())
-    ->throws(Error::class, '"unknownMethod" is not a valid meta for enum "Cerbero\Enum\BackedEnum"');
+    ->throws(Error::class, 'The case Cerbero\Enum\BackedEnum::one has no "unknownMethod" meta set');
 
 it('runs custom logic when calling an inaccessible case method', function() {
     Enums::onCall(function(object $case, string $name, array $arguments) {
@@ -450,7 +450,7 @@
     ->toBe('red');
 
 it('throws a value error when attempting to retrieve an invalid item', fn() => BackedEnum::one->resolveItem('invalid'))
-    ->throws(ValueError::class, '"invalid" is not a valid meta for enum "Cerbero\Enum\BackedEnum"');
+    ->throws(ValueError::class, 'The case Cerbero\Enum\BackedEnum::one has no "invalid" meta set');
 
 it('retrieves the value of a backed case or the name of a pure case', function() {
     expect(BackedEnum::one->value())->toBe(1);
diff --git a/tests/PureEnumTest.php b/tests/PureEnumTest.php
index f6b9d9c..0ecd1da 100644
--- a/tests/PureEnumTest.php
+++ b/tests/PureEnumTest.php
@@ -403,7 +403,7 @@
 });
 
 it('handles the call to an inaccessible case method', fn() => PureEnum::one->unknownMethod())
-    ->throws(Error::class, '"unknownMethod" is not a valid meta for enum "Cerbero\Enum\PureEnum"');
+    ->throws(Error::class, 'The case Cerbero\Enum\PureEnum::one has no "unknownMethod" meta set');
 
 it('runs custom logic when calling an inaccessible case method', function() {
     Enums::onCall(function(object $case, string $name, array $arguments) {
@@ -458,7 +458,7 @@
     ->toBe('red');
 
 it('throws a value error when attempting to retrieve an invalid item', fn() => PureEnum::one->resolveItem('invalid'))
-    ->throws(ValueError::class, '"invalid" is not a valid meta for enum "Cerbero\Enum\PureEnum"');
+    ->throws(ValueError::class, 'The case Cerbero\Enum\PureEnum::one has no "invalid" meta set');
 
 it('retrieves the value of a backed case or the name of a pure case', function() {
     expect(PureEnum::one->value())->toBe('one');