If you can't think of what to write, tough luck; write anyway. If you can think of lots more when you've finished the three pages, don't write it; it'll be that much easier to get going next day. ↗
I have always distrusted memoir. I tend to write my memoirs through my fiction. It's easier to get to the truth by not claiming that you are speaking it. Some things can be said in fiction that can never be said in memoir. ↗