Suspension of Disbelief

I am science oriented, and have a grounding in reality (I think?), so sometimes a movie just stops being fun when something completely unrealistic happens. I’m okay with a lot of things, like outrunning explosions doesn’t bother me much. But six squeaky clean enemy vehicles show up in the middle of muddy nowhere just at the exact moment the hero passes by?
I don’t know why sometimes I can roll with it but other times it ruins the movie for me.