You could ask another question that your comment directly answers, and put a comment linking to that question on the original question. You then have a post that is helpful to both the OP and people who are searching for an answer to the question you asked. Others who wanted to add similar comments have a question where their answers will be on topic.
Using your first examplefirst example, you could ask a question like "What is the age of accountability?" You could then post an answer that elaborates on the age of accountability, and post a comment on the original question like "This question might be helpful" that links to your question.