Roxy, happens all of the time.
For emails I have a few sticky notes that I just copy and paste as a reply.
I usually don't answer my phone.. If they don't leave a voicemail I will text, "have we met?" And if they say no, then I reply with the sticky note that pertains.
It takes a lot of stress off of me having to rewrite every time what feels like the same thing..
I will get emails that ask if I am in a place that I was at for a week over six months ago.. Men look at photos, look for key words, then contact. They don't always read all of what we write, it's just how they work.