I go home for lunch & watch GH, so I almost always miss the first 15-20 minutes. I plan it a little late so I can watch up to the end. If I have any errands to do on my lunchbreak unfortunately my GH watching pays the price, so sometimes I miss more.
That's why I'm often confused when I watch the show. If anything happens at the very beginning of the episode, there's a very good chance I didn't see it. That leads to a bit of confusion.
During particularly big storylines, I sometimes tape so I won't miss important stuff. But I don't want to load up my To-Be-Watched stuff any more than necessary.