Why can't I close my own questions ? I should be able to close it once while I have either received an answer or I find the question was either too broad or whatever
If your question can't be answered for some reason, you can skip over closing and just delete it yourself. Once the question gets answers it can't be unilaterally deleted anymore because other people have contributed to it; enough people will need to vote to close/delete it
When I think of it as 'as an example of one person's experience that others may likely have' instead of 'my question' I find it makes more sense to me that should have to leave it there for others.
Just because you are satisfied with an answer that the question has received, that's no reason to close it. If you accept the best answer, that marks the question as having been satisfactorily answered, so people know that you don't still need an answer. But if the question is clear, on-topic, well-scoped, objective and unique, it should be left open, so new and better answers can be added later, and future searchers can benefit.