As a Swede, moving back home after almost a decade, what should I rediscover in Stockholm? :)

What are good things to do at night? I have a 10 hour layover in Stockholm starting at 1 am and looking to do something intresting. Anything I can… 

Hitting Stockholm for 5 days in late January. What should we do? Museums, galleries, neighborhoods, outdoors, etcetc. ?? and any food/drink recs also welcome ??