look (at something) through rose-coloured spectacles
To assume a generally optimistic and cheerful attitude (toward something); to focus only or mostly on the positive aspects (of something). Primarily heard in UK. I know nostalgia can be misleading, but I really look at my childhood through rose-coloured spectacles. I think Mary is only capable of looking through rose-coloured spectacles, like she's in complete denial of the negative things in life!