Yep 
, since what probably 99% of people need is one recursive route (or maybe two), one can simply bypass the extensive, but complex, explanation on how it works and why it works and just remember three steps with 10, 11 and 12 and implement them as an act of faith:
I.e., easily condensed in a 12 points 
numbered list: 
:
1. Imagine here a complex explanation of how recursive works, then ignore it.
2. Imagine here a complex explanation of how recursive works, then ignore it.
3. Imagine here a complex explanation of how recursive works, then ignore it.
4. Imagine here a complex explanation of how recursive works, then ignore it.
5. Imagine here a complex explanation of how recursive works, then ignore it.
6. Imagine here a complex explanation of how recursive works, then ignore it.
7. Imagine here a complex explanation of how recursive works, then ignore it.
8. Imagine here a complex explanation of how recursive works, then ignore it.
9. Imagine here a complex explanation of how recursive works, then ignore it.
10. Both routes must have scope=10
11. The “narrow” (/32) route to the canary must have target-scope=11
12. The “wide” (0.0.0.0/0) route must have target scope=12
Easy to remember and good enough for the 99%, the 1 % can take their time reading (and hopefully understanding) the extensive and complex explanations by anav, Chupaka or CGGXANNX, before implementing steps 10-12 
.