You actually CAN'T stop. Look back at the history of iOS app dev. It's not that long of a history, but look at what's changed. Look at the changes just in Xcode alone. Look at Storyboard and the new size API.
It's actually quite a bit just to keep up. You have to strike a balance between using what you already know and learning what's new.
Just like the iPhone itself, they add new things about every year.
When the SDK first became available, it often took around 2 to 4 weeks for experienced C and C++ programmers to get used to the strange Objective C syntax and conventions sufficient to do app size native coding, and maybe another couple months to learn enough about the iOS frameworks to throw together one of the earliest iOS Apps Store apps. However the bar of expected app features has gone up quite a bit, and the iOS API has gotten much larger over the past 7 years, so it would take longer today. On the other hand, Swift is said to be slightly easier to learn than Objective C.
If you complete the Stanford iOS course, includingall the recommended pre-requisites, that's a bit over 1 year of university level coursework.
That's just to get started. But one can invest years of study and still not have learned all the iOS APIs, frameworks and system esoterica. Depends on what kind of app you want to develop. Simple or close to award winning.
You need to keep practicing.
Even after six months, you'll hit weird things happening like UITableViewCell's -(void)prepareForReuse method creating weird layout issues for your custom table cell.
There will be a time where you can more or less get through all your issues and bugs without getting stuck and giving up though.
You will never stop using Google as a search or StackOverflow or this forum.
I wouldn't depend too much on Interface Builder though. They change it so much, but writing out your layouts in code will always be consistent.