At my last apartment my LL would only allow a single number per apartment... well I was sharing the apartment with someone else and I was sick of being the only person to get called. 30 seconds of Googling revealed the user manual for the intercom, and of course the default password of "5555" was still set on it...

I programmed both our lastnames and phone numbers to our apartment unit number. I did that in 2014 and I moved out in 2016.

To this day -- NINE YEARS AFTER MOVING OUT -- I am still getting calls whenever someone hits #25 on that intercom.

I should have done the 1-900 thing :D

Not really...

If my outermost box says "Tools", a box in that box says "Automotive", and the box in that box says "Trim Removal".

There's no chaos, I drill down from the generic to the specific and find what I need.

Using Tags (keywords, etc) you can cross reference things too -- for example Tools that may have uses in both the Automotive, Household, Computer realms get those as keywords, and ideally the tool will have a primary role so it can exist in that box, or otherwise if it truly doesn't belong in any one box then it can just be in the Tools box along w/ the boxes that contain all the task-specific stuff...