You wear rose-colored glasses when you think about your old school.
rose-colored glasses
idiomA cognitive or perceptual bias where an individual views something in an overly optimistic or positive light, often failing to recognize its negative aspects.
Origin
first recorded 19th c.Phrase appears as early as 1830 according to OED. From rose-color or rose-colored (meaning "pleasant"), from the notion that roses are widely regarded as uncommonly beautiful.
She looks at her past relationship through rose-colored glasses, forgetting all the arguments they had.
The politician viewed the economic situation through rose-colored glasses, ignoring the clear signs of decline that worried the rest of the public.