I don't think it is possible to ever truly know our bodies completely. I have had that many changes to the way my cycle is, the way my af is, the way my body reacts to af, that I no sooner 'know' it, before I have to get to know it all over again. So I don't think it is entirely ignorance either LOL. but I think ignorance could be masked as being you just not needing to know it at that time. When I'm not TTC I don't really need to know when I O. And now I don't even count the days of my cycle, AF just turns up when she turns up (Like last night when she did and DH had to take a cold shower this morning instead when I told him ) I note the changes over the course of a cycle and I know what is 'abnormal' for me, but I don't pay attention to it in the same way I did when I was in TTC mode, it's a different way of looking at it now. Using fertility friend could be seen the same way. I have seen threads every now and then that says FF has said they 'should' have ovulated, but in reality they have no signs, so they doubt themselves or doubt FF etc.