The golden rule of estimating: double it and add 20%. The sooner you start doing that, the sooner you start underpromising and overdelivering instead of the other way around.
2hrs === 4 days.
A week == 2mths.
Anything past that would never get done.
He was a cynical bastard but not a bad guy and sadly he was in a lot of dysfunctional environments not that far of the mark.
The golden rule of estimating is to measure past estimates and use them as a multiplier in future.
The platinum rule is to stop estimating because it's useless.
20*2*1.2 = 48
20*2.2 = 44 // I, also, was confused myself at this point
2 *1.2 = 2.4 // not 2.2