I have been training AutoCAD for a good number of years now and I see the same thing happen over and over again when newbies attend their first AutoCAD training course or even when I have an attendee coming for a refresher course.
Some of these funny quirks if we could call it that is not per say a quirk but how the software is supposed to operate but because of either years of working on an old AutoCAD or working in a different software environment, we have to remember the saying “old habits die hard”. \
Lets look at the selection methods that AutoCAD has. You can either pick each object one by one or use the window or crossing selection. By clicking once on the screen an running your mouse right to left (crossing) and then clicking again, anything that green window touches will be selected.
If you select on the screen and run the cursor from left to right (window) only objects fully inside the blue window will get selected.
The one that always gets everyone and that’s the lasso select.
This selection method which gives the most issues is the lasso select. Not because it is difficult but because of the way it is activated. The issue that gets everyone is that to activate the lasso selection is that you hold in the left mouse button and move the mouse to do your selections. Because of “muscle memory” ie other software products the new users keep on activating lasso and not the window or crossing selection.
You can de-activate the lasso selection in the options if this is not your cup of tea. Select options and then navigate to the Selection tab and deselect Allow press and dag for lasso.