I found the level of complexity too confusing. Add in the very loud music and sound effects drowning out some of the dialogue and I was lost. I kind of knew what was happening and understood the premise but couldn't keep up with the plot points, pseudo science explanations, and character motivations etc.I don't think its enough to say "just go with the flow and enjoy the ride". Nolan failed to engage me properly which means he didn't do his job. To date I've loved his work but this was a confusing jumble too far. Technically of course marvellous but that's not enough.