Lyric discussion by NameGotTaken 

Cover art for Museum of Idiots lyrics by They Might Be Giants

The museum of idiots is a bar. The place where she met him, where she may forget him.

She left him, he still loved her so he went back to the bar where he met her and drank his days away, expecting her to come find him.

He thinks of her relationships as temporary (made of wood) and is just waiting around for her to take him back.

So the bar is full of guys just like him, a museum of idiots.

My Interpretation