You should know two things about the year 1988. First fact: Glam metal band Cinderella released a piece of golden truth in the form of the power ballad “Don’t Know What You Got (Till It’s Gone).” Second fact: Susan Grover and Richard Thurston were putting up art shows for their local artist friends in their Eastlake apartment that year. Soon they moved downtown and became the rock-solid art gallery Grover/Thurston. Grover/Thurston lived for 24 years, freight-training right through the divorce of Grover and Thurston and keeping going, but now it’s closing down (no crisis, they just want to move on). You don’t know what you got till it’s gone, people, unless you get down there and see the final group show this winter. (Grover/Thurston Gallery, 319 Third Ave S,, 11 am–5 pm, free, through March 1)