You can right click and select "Recent Commands" ...
If rmb in the screen you get a menu and can select Save Selection or use Add to Favorites.
If you're drawing a line and hit escape which will close the line drawing feature, then hit enter and the line drawing pencil will be ready to draw again..
RMB in any tool bar, select Customize, select the keyboard tab, then sort by the short cut tab, Highlight all the commands with shortcuts, and past into Excel.
Like you I do not have all these memorized.
I clean it up and print it out and have it taped to the side of my monitor. Currently the only shortcut that is not standard is the Alt+V for the Tile Vertically, which I like for using 2 monitors.
You can also create any special shortcut which you use often.
Hope this helps.
In case you didn't know, you can print the shortcut list directly from the dialog too and using that method, it will print the icons along with the names. Simply go to Tools, Customize, Keyboard, and next to the Show label, choose "Commands with Keyboard Shortcuts" so the list is reduced to only those with shortcuts. Then select the Print List button. You can also use the Copy List button if you want to put the list into Excel like you are currently doing if you want to format it differently before printing.
Not sure if this is what you are looking for but if you know that you will be selecting certain features multiple times you can highlight them in the tree and select "Save Selection Set".
Sorry I'm about a year and a half late to this, but I think you're looking for the Previous Selection tool. The only way I know how to access this is to right-click in empty space and activate the command from the Context Menu. It looks like this:
This should restore any selections you had prior to clearing your cursor.
I hope this helps!