I did. Well, I Bing'd bokeh.
What I learned is that bokeh is a word made up in 1997 by the editor of
Photo Techniques magazine. The editor learned the Japanese word, boke, meant blur or haze but apparently missed that the Japanese word boke is also used in the context of a mental haze, or senility.
I also learned the new made up word refers to the aesthetic quality of the blur in out-of-focus (OOF) areas of an image, or "the way the lens renders out-of-focus points of light".
Further investigation lead me to understand that bokeh is not adjustable because it is an inherent property of the lens construction, there are 2 kinds, and that many people use the term bokeh incorrectly to describe a shallow depth-of-field (DoF) or blurred background.
Apparently, the number and shape of the lens aperture blades is a major factor in determining the aesthetic quality of the blur in out-of-focus areas of an image, with the shape of the lens aperture the aperture blades form having an marked influence on the subjective quality of bokeh. The closer to perfectly round the lens aperture is, the higher the aesthetic quality of the blur in out-of-focus (OOF) areas of an image will usually be.
In short, not all lenses that can produce a shallow DoF, also produce good or quality bokeh.
For example Canon's inexpensive EF 50 mm f/1.8 II lens is touted for it's ability to produce a shallow DoF, but the aesthic quality of the out-of-focus (OOF) area the lens produces is considered jittery, jarring, nervous appearing, and generally of very poor quality. The lens only has 5 aperture blades, they are not curved, they have sharp edges, and they don't come close to making a round lens aperture.
Canon EF 50mm F1.8 II Lens Review: 5. Conclusion & samples: Digital Photography Review
Conclusion - Cons
Harsh and distracting bokeh due to pentagonal aperture
By the same token Nikon's AF 85 mm f/1.4D lens has been nicknamed "The Cream Machine" because of the ultra smooth, very pleasing visual quality of the OOF areas it produces. the lens has 9 curved aperture blades, and the blade edges are also curved so the lens aperture is a fairly close approximation to a perfect circle.
As far as image #1 the OP posted the brighter brown blurred background elements form nice leading lines to the intended main subject. The lighting leaves some to be desired because the stem is heavily shadowed.
You might want to Google/Bing/Ask: Depth-of-field, Circle of Confusion, and Airy disk.