Since around Revit 6.0 (before Autodesk added their ribbon), the singularly biggest annoyance in Revit has been, having to double-click on toolbar buttons -- those buttons only work about half of the time, if you click fast it doesn't register at all, and you have to circle back and click again, or just habitually double-click every ribbon button every time.
It's not a hardware issue,(happens the same way in dozen+ offices), it's exclusive to Autodesk software (doesn't happen with Adobe, Microsoft, Bluebeam, etc), it's not a user issue (reported by whole office of 20+ Reviteers), and I can help be reminded of the similar flawed design of AutoCAD that forced users to habitually double- /triple- /quadruple-tap the ESC key after every command... is this some forgotten easter egg from the developer, designed to turn us all OCD?
Either way it's definitely time to fix it, that's for sure!