One of things I love about the Smalltalk system is how it lets me keep focus on what I'm doing. Working on my friend's website, there are lots of pieces of data that I make pages to display, as any programmer can relate. And also as any programmer can relate, I have the issue of how to populate this "model data" to test if my display pages are working.
So I have two choices: (1) I can create the whole GUI that lets one enter data or (2) I can put some extra code in my program to populate the data, for testing.
The problem with 2 is not big, just that I'm wasting time writing stuff I will have to take out later, just so I can test. Choice 1 doesn't have that problem, but it does break my focus. I have to stop working on what I am really interested in: the display pages, to work on a data input page(s).
But Smalltalk has another option (my favorite in fact): I can simply navigate through the live web site objects (via 'find instance of') until I find pages and insert the model data directly.
This way I can keep on working on what I am focussed on right now. In traditional languages you must choose one of the above 2 options, but in Smalltalk option 2 has been done for you generally in the tools.