Am I supposed to read all these twitters?

This morning I had to page back twice on twitter.com to read all the tweets that had come in overnight. I don’t normally do this, normally I just read whatever twiteriffic gives me, and ignore everything else, but I was looking for a specific one. But am I expected to have read them? Are people going to assume that I’ve seen everything they’ve twitered? I do enough catching up in the mornings already without having to remember what the most recent twitter I’ve seen was and paging back till I see it.