Writing is a very associative process. Everything is related. You see an image and it makes you remember an experience. The color on a poster reminds you of your favorite cereal (because it is the color that it makes the milk turn).; just keep forging ahead.
It's why we struggle so often with originality. We know our story has been told before because we associate the concept with other stories that have the same or similar concept. But in reality, your story, no matter how similar it may be, is a unique and original creation (unless you outright stole it).
One of the hardest things you can do is free yourself from association. Put on your blinders and move forward. Worry not about any distractions or any similarities to anything else. Just live in the moment.
I recommend this for life as much as writing. Do not avoid an activity because you associate it with some other experience. The activity you will do will be as unique and original as your stories.