I am not a programmer by training, yet REALbasic made creating my own word processor possible. The initial version of Z-Write (in 1998), which I whipped up for my own personal use to test the concept, was working (add/delete Sections, switch between Sections, open/save the file) in less than 20 hours of programming time. That's partly because I was able to reuse some code from another project, but mostly because REALbasic is so easy.
Adding extra features like importing and exporting, find/replace, printing, preferences, glossaries, and polishing the program took many hundreds of hours.