My earliest memories of a museum would be Stockport's Vernon Park Museum, a frequent place for day trips with my gran. I would sort of hide behind her from the cave of neolithic men. Manikins, ugh. I loved that place, as it was a very odd collection of stuff and things, with a great little video about the history of Stockport. It probably started my fascination with how old things can help us see the world a bit differently.
It's a few years since I've been back, and it seems as though the best of the displays were cherry picked out when creating a more centrally placed museum (Stockport Story at Staircase House) and people are now generally disappointed with what's been left and the care it receives.
Still a great set of gardens and park though, and worth a visit just to drop your jaw at the Blue John window - yup looks like stained glass but is really made from stone!