You should ask Scott from Specialized Dynamics and AzBushman about the importance of a forward assist. Both have gottne nailed by a bolt that comes out of battery.
Scott and I were out one day, and I called in a bobcat, about 30 yards in front of him. He placed his crosshairs on it's head and pulled the trigger, "CLICK." The cat heard it, looked at him, but the caller started again, and the cat turned it's attention back to the call. Scott stayed calm, as a good shooter with a malfunction should, and eased his 1911 .45 from his holster. he proceeds to shoot and hit the cat. It ran off, but we tracked it and Scott put it down with my Specialized Dynamics .223 AR. We checked his rifle, and found that in getting out of the truck the bolt had come out of battery.
Bushman was out with me on his first predator hunt, and we were cautious about noise discipline, so when he lowered hi bolt he did so very carefully. The bolt stripped off the round from the mag, and closed, but it didn't rotate and lock. 90 seconds into the stand a bobcat comes walking right at him, he squeezes the trigger, and "CLICK". Bushman eases the charging handle back, and dropped the bolt hard, immediately he pulls the trigger and the cat goes down.
When I am going out on a stand I will "bump" my forward assist just to be safe. It's like everything else, get into a pattern, and you will make less mistakes, and forget fewer things.