A lot of programmers who have an easy time coding (even in a new language) are relying on several years of experience and StackOverflow. When I look at a select box on a page, my brain automatically thinks "okay, was this rendered using HTML or JS? what styles have been applied? is there an onchange callback? how is the data being populated? what's the data model look like? is it using two-way data binding or posting with a form?" I can only speculate about these aspects because I've had to build them all before. I absolutely struggled when I first had to deal with new concepts like Javascript frameworks or unit testing, but after sticking it out for a few months, I was able to internalize how they work and see the underlying design patterns, rather than just the implementation details.

If you could elaborate on certain issues that you're running into, we might be able to give you more insight into what exactly is tricky about it.