I don’t like GIMP. I’m not very familiar with it, and I only open it when I have relatively complex requirements for an image. It invariably takes me quite a while to learn how to use the software to do what I need. Spending that much time wrestling with an application sort of makes me not like that application.
One of the tricks I have learned is to avoid the internal help. I find help online, either in YouTube videos or on web sites that someone was kind enough to create. The problem of the day was how to blur the background of an image, while keeping the subject matter sharp. I found a nice guide here:
Further, I found that using Lasso select (L) and then paint bucket (ALT-B) to color my blur layer was much faster than playing with a paintbrush as they described.