Really, it's just a matter of scale. Like their larger cousins, the brainstorms known as headaches are quite capable of wreaking havoc, and generally clouding what might otherwise be considered a perfectly nice day. Like blizzards, some headaches remove depth and perspective, leaving a two-dimensional landscape that isn't worth navigating. Others are navigable, but leave the traveler with a sense of wasted time and effort; some settings simply aren't worth the trip.
On the other hand, storms can be intriguing, and even beneficial. Sometimes the fresh perspective — especially when reconstruction is complete — is worth the chaos. To quote Craig Conley in the context of a recent post at COLOURlovers.com, the "creative urge dragged down yet not knocked out by chronic pain" reminds us of the possibility of renewal in the aftermath of the storm, regardless of its relative scale.