Top reasons, from least to most used:
- Shortage of time
- Neighbors making too much noise
- General insecurity / Having an "off" day
The last one sadly happens more often than I'd like! I mostly concern myself with how I sound, and how my accent sounds to native speakers seeing as English is not my native language... Then I obsess over one or the other and end up switching from English to American, then back to English because one feels fake and the other feels way overdone to my ears... If I can get over this my productivity should be way higher