Coming up with an awesome hook for a movie is just one part of the filmmaking process - the real challenge comes in following through in the execution, and ensuring that said concept remains compelling to the very end.
Sadly it's far more common for intriguing films to fumble the ball half-way through, struggling to sustain the surging early momentum of their killer premise all the way to the end.
Inspired by this recent Reddit thread on the subject, that's absolutely the case with these 10 movies, each of which ditched their best, smartest, and most inspired ideas long before the end in favour of something far more familiar and unsatisfying.
Were all of these movies terrible as a result? Absolutely not, but that early promise was ultimately squandered amid a second half which failed to live up to it.
From one of the most ingeniously original sci-fi concepts ever to a daring superhero horror movie setup, a potentially Oscar-worthy satire, and everything else in-between, these 10 potentially awesome films threw out their most appealing concept long before the story was over, for shame...
10. An Alcoholic Superhero Seeks Redemption - Hancock
In the grand pantheon of intriguing movies that became something demonstrably worse half-way through, there's perhaps no topping Hancock.
The Will Smith-starring superhero flick was marketed as a black comedy about the titular alcoholic superhero, who attempts to redeem himself in the court of public opinion by teaming up with a PR consultant, Ray Embrey (Jason Bateman).
And for roughly its first hour, Hancock is basically that - an outrageous, irreverent piece of work where an irascible, troubled superhero tries to get his life back on track yet struggles with his own penchant for self-sabotage.
But the movie falls off a dramatic cliff once it reveals the big twist, that Ray's wife Mary (Charlize Theron) also has superpowers and is in fact Hancock's former lover.
At this point Hancock mutates into a bizarre supernatural romance which feels wildly at odds with the movie it was up to that point.
The chaotic shenanigans of the first hour are largely forgotten in favour of a decidedly less interesting love story, ensuring the movie ends on a series of increasingly underwhelming down-notes.