Coming from Personal Brain left me a little confused about adding thoughts in BrainEKP. In Personal Brain, the principal method of generating a new child thought from external material is to first click on the expectant parent thought, then drag and drop the content to the plex. This creates the new thought as a child, automatically named with the file name, and attaches the file. This works for urls and files, so that when you click the icon on the left of the thought's title, the content opens in the browser or the native application.
Things are somewhat more complex in BrainEKP and vary, depending on the desired content of the thought.
FIles are the simplest to add as thoughts. You can drag and drop a pdf or a doc (or any other kind, for that matter) onto the plex. This will pop up a new thought naming menu. After you name the thought (probably using the name of the file), the thought is created, linked as a child or sibling to the current thought, and the file is its primary attachment. The file's contents display in the bottom pane.
Alternatively, and much harder in my mind, you can create a new thought as described in the Weblinks / URLs section, below, and then click on the "Add attachment" link at the top-left of the lower pane and add a file. This probably is only useful for adding a file after creating a thought.
The text you are reading is an example of direct entry of text (in this case, formatted as html). This, too, is relatively simple:
== Ollie