Taka“What is the difference between these below?
・We don't think about how we should behave.
・We don't think how we should behave.
”
The second seems more like very informal speech for, approximately,
We don't consider carefully how we should behave.Personally, I don't use that expression, though I have heard one or two others use it. It seems odd to me.
On the other hand,
We don't think about ... means that it doesn't enter our minds. The subject never comes up, never presents itself to our minds for consideration.
CJ