I don't think anyone wants a reader to be completely lost - certainly not to the point of giving up - but there's something to be said for a book that isn't instantly disposable, that rewards a second reading.
Many times I've sat with a camera and another actor and seen all their fears and insecurities and struggles. You want to support them and help them as much as you can.
Anyone who tries to write a memoir needs to keep in mind that what's interesting to you isn't necessarily interesting to a reader.