6. Back To The Future (1985) – Marty’s Parents Would Recognize Him

Time travel and plot holes go together like Michael Bay and explosions: where there’s one, you can be pretty sure the other isn’t far behind. Even though Back to the Future is one of the best time travel movies ever made, it isn’t immune: there is one nagging plot hole from the film’s ending that defies explanation. What’s more, it’s a direct result of Marty’s encounter with his parents in 1955, further proving that traveling back in time to meet your own parents is NEVER a good idea.
Though Marty avoids accidentally introducing himself using his real name, he adopts the name Calvin Klein (thanks to his underpants). Both of his parents know him in 1955 as Calvin, and after a few days of choice interaction (manipulating his father and rejecting his mother’s romantic advances) he manages to set them up with one another, thereby ensuring he doesn’t cease to exist. However, as they each met him in 1955 as Calvin, when he’s actually born 30 years later, George and Lorraine may be in for a surprise.
As Marty grows up, they’d surely realize that he looks awfully like Calvin, the young man responsible for their entire relationship – the same young man that Lorraine was desperately chasing before meeting George, no less. At the very least, Marty looking identical to “Calvin Klein” should raise suspicions of infidelity, but a DNA test could clear that up. However, this would then lead to several awkward questions regarding the mysterious stranger with the obviously fake name that set them up, and it’s not a plot thread that’s ever picked up or even addressed. It may be minor and largely inconsequential, but it’s certainly an annoying little plot hole.