[bztzt]

even if you're "good at" hierarchical filesystems they have a few inherent problems:

1) there's overhead associated with coming up with a hierarchical file structure, keeping it updated whenever your problems or your understanding of them change, etc.

2) there's overhead associated with always remembering to put a file in the "right" place every time you save it, actually navigating there to save it, and then fishing it out of the "right" place every time you need a file (getting to a file with search can sometimes be faster than navigating to it even if you know exactly where it is)

3) there is no perfect hierarchical structure for information; there will always be situations where x/y makes as much sense as y/x and both are sometimes inconvenient

this is not to suggest that search, tags and other alternative mechanisms don't have their own problems.