Somewhere in the middle of the steep climb up Filbert Street Steps to Coit Tower, you might begin to wonder if it’s worth the trouble. Well, take a breather and look around. Already you’re passing hidden cottages along a wooden boardwalk called Napier Lane, sculpture tucked in among gardens flowering year-round, and sweeping vistas of the Bay Bridge. If you need a few words of encouragement, the wild parrots in the trees have been known to interject a few choice words that your gym instructor would probably get sued for using.