>Learn how to zone focus because I take like 30 seconds to take just one pic (to figure out the right exposure and the right focus)
>Having a hard time trying to implement zone focusing on myself because I don't know how long is 3 meters actually is

"ahh, that has got to be 4 meters"
*check out the measure with my phone
*nope it's actually 6 meters"

"Mmmm I guess this one is definitely 7 meters"
*nope it's actually 5"
Am I seriously the only retard here or is this common?