First, the good (aka lucky):

About 4 years ago, I was flying BOS-DEN. I was booked on the ~8PM flight, but arrived early enough to take the ~4PM flight. I got the last available seat on the earlier flight. On the way in, the 4PM flight hit a bird, damaging two fan blades in one of the engines. Ended up with the creeping delays while the plane was inspected. 7 PM rolls around so I switched back to the 8PM flight figuring it would be a close second if not first. Apparently I ended up with the last available seat on the late flight - lucky me! 9 PM rolls around and both planes are still on the ground - inbound aircraft had delays from ORD. BOS started to shut down and we were advised that we could wait for the plane, but 1) there was no guarantee that it would be able to take off because the crew was getting close to going over and 2) if we left security, it was closing for the night so we wouldn't be able to get back in, so if we wanted a chance for a real bed, they'd give us hotel vouchers and we could take them at 9 or sleep in the airport. I opted to stay, ended up on the flight that finally departed at 2 AM - 5 minutes before the crew went illegal or so we were told - and ended up getting op/upped to F because to dead-headers wanted to sit together. Very lucky!! ^^

Now the bad:

And, unfortunately, these are what I usually experience...
1) Creeping delays of only 10 minutes at a time so that I never get an easy update message, even when the total delay comes to 2 hours or more.
2) Unannounced delays. I've sprinted through airports before, arriving at the gate 10 minutes prior to the scheduled departure, only to find out that the inbound aircraft wasn't there, but there was no indication of a delay on the monitors.

What I've learned:

As soon as I see a delay, I ask a GA why the delay exists.

Is it mechanical? If so, I'm more inclined to wait by the gate since those are typically known delay times.

Is it an inbound aircraft? If so, what flight is it so that I can watch the monitors for that? Yes, I know that the inbound aircraft can change, especially if there's a mx issue with the inbound plane. But, if the inbound craft is among many inbound delays, I'm just as happy to wander off until I see that the inbound has arrived. Never missed a flight yet (knock on wood).