Is it natural to use this idiomatic expression in the following context? I want to say that I am not sure but probably it was about six years ago.
So a few years ago, err, six years ago off the top of my head, when my daughter was in primary school. we went to ...
According to dictionary it can be used to mean "from the knowledge you have in your memory". But I am just talking about a personal experience. In the examples I have seen, it is usually used to talk about knowledge that can be verified using some sources of information, but the speaker has not verified it yet. It seems that they have seen the data somewhere, but right now they are just telling it from their memory. For example:
- "What's the capital of Mauritania?" "I don't know off the top of my head, but I could go and look it up."
- "How much can we expect to earn this quarter?" B: "Off the top of my head, it should be around $200,000, but I'll have to check the
figures when I get to the office."
But in my sentence, I am using this expression to talk about a very personal thing which is in no way can be verified using a book, chart or any kind of data from another source. So maybe using "off the top of my head" is not appropriate for personal things? I mean the things that I haven't seen somewhere but something that I just know.