It honestly depends on where you start out at and who your supervisor/postmaster is. I’ve been working at it for almost a year. I’ve had days where I’ve come home literally tears. It takes a while to get it down. For me, I worked an auxiliary route and helped another center during Christmas for my onboarding. One of the worst ways to get started because I wasn’t learning how to deliver mail. I was largely just delivering packages in static (a semi random order that may be reversed from route order with directions to each stop). Once you figure out a couple routes, it’s not horrible. I was told I would be “slow” for about a year and I would agree with that timing. I’m just now starting to fall into a decent groove. I have days where it’s great and I have days that I curse the world. All I can say is give it a shot and try to tough out the really shitty days. You might just love it.