Last May I was flying from BWI to SFO on United departing at 8am. The weather was bad and at 10pm the night before I checked the status of the flight online and it showed 2 hour delay (10am departure time). I double checked again at midnight before I went to sleep and it showed the same delay.

So, if the flight is delayed 2 hours, I can get a few more hours of sleep

Wrong! I get up around 7:30am and when I check the flight status it shows an ontime 8:00am departure

I debate for 2 minutes as to whether I can make it or not since the hotel is only 10min from the airport. I go for it and even after returning the rental car, I'm in the security line at 7:50am when I find out that ultimately the flight was cancelled for mechanical.

Anyways, I was wondering if anyone else had experienced something like this in the past. Should I have assumed the flight was going to depart on time before going to bed? Even though the website status showed delayed? Just trying to understand where I went wrong.