You can go a long way with just general purpose tools, and maybe you need to get some specialist tools for certain jobs, but this is by far the most useful convenience tool I use. It grips the cable, then locks in place at the desired tension. Sooo much easier than trying to hold everything in place while you tighten it up when setting up brakes and gears.
Before the Internet became the advertisement generator we know and love today, interspersed with interesting information here and there, it was originally a network of computers largely among various universities.
The best unnecessary tool
The First Search Engines, Built By Librarians (hackaday.com)
Before the Internet became the advertisement generator we know and love today, interspersed with interesting information here and there, it was originally a network of computers largely among various universities.