We Don't Know Who We'll Run Into

Besides your planned meetings, demos, and sales calls...you get plenty of random opportunities to run into people who may benefit or influence your startup in one form or another.
Have you just held the door open for the mother of your future investor? Is the person behind you in the grocery line a Full Stack developer currently looking for her next position? Did you just step onto an elevator with an ideal user and product evangelist riding 10 floors up with you?
You never know who you may run into that could influence your business and help you grow, improve, and change the world.
For that, your elevator speech needs to be ready at all times, along with your story, and you need to be open to adapting and delivering the message so your value is clearly understood no matter who's listening.
If the person is your next user, they have a specific understanding and need. If the person knows a person, they have a different knowledge base and will need just enough to pitch it forward. And if they're someone creative to brainstorm with, you need to be ready with a 'Yes, and' approach to keep the ideas coming.
The bottom line: just like you never know what will actually hit, you don't know who you'll need to sell to, in one way or another. Be prepared and stay in the zone.
And honestly, start with just being a human being first. Say hi. You may not have time for the full pitch, but you'll always have time to make a first impression...and leave the door open for a future one.