Explicit note on local bean access within @PostConstruct method

Closes gh-27876

src/docs/asciidoc/core/core-beans.adoc

@@ -8883,7 +8883,6 @@ classes, each depending on beans declared in the others:
 	}
 ----
 
-
 There is another way to achieve the same result. Remember that `@Configuration` classes are
 ultimately only another bean in the container: This means that they can take advantage of
 `@Autowired` and `@Value` injection and other features the same as any other bean.
@@ -8895,6 +8894,11 @@ classes are processed quite early during the initialization of the context, and
 to be injected this way may lead to unexpected early initialization. Whenever possible, resort to
 parameter-based injection, as in the preceding example.
 
+Avoid access to locally defined beans within a `@PostConstruct` method on the same configuration
+class. This effectively leads to a circular reference since non-static `@Bean` methods semantically
+require a fully initialized configuration class instance to be called on. With circular references
+disallowed (e.g. in Spring Boot 2.6+), this may trigger a `BeanCurrentlyInCreationException`.
+
 Also, be particularly careful with `BeanPostProcessor` and `BeanFactoryPostProcessor` definitions
 through `@Bean`. Those should usually be declared as `static @Bean` methods, not triggering the
 instantiation of their containing configuration class. Otherwise, `@Autowired` and `@Value` may not