Trying to think of a catchy or clever novel opener can be a major discouragement from just getting the pen to the paper and formulating that first paragraph.

It can be much easier to start your writing a bit further in, where you have a rough idea of a scene, and letting the characters and the action work themselves.

In fact, this is a good way to create bridges through tricky parts, where you know the current scene, the scene after the next one but no idea how it got there. Instead of struggling with the blank page for too long, skip the unknown scene and keep writing. And later on you'll likely have a good plan for filling in the bridge.

It's much easier to go back and fill in the gaps when you've figured out the 'voice' of your novel, and have a good understanding of the characters and their quirks.

You may also realise you can cut so many of the gratuitous scenes that were useful in your mind for connecting A to B in terms of worldbuilding and plot progression, but are extraneous to the reader.