Here's some very good advice for aspiring and early stage founders: don't be wedded to your business idea, instead be wedded to your market/ target customer base.
The biggest concern with many early stage founders is that they are wedded to their product. Making a great product is not the end objective of a business. Filling a gap in the market is how a business grows. And for achieving this, you have to pay obsessive attention to your customer.
This advice, while easy to give (most VCs will give you the same advice) is really hard to implement. It's tough to realize when you're wedded to your idea. Getting that self awareness that you're wedded to your product instead of your market is 90% of the job done.
A lot of successful startups are product first companies who got lucky, got funded and then the investors drove it to scale up. But you need to be extremely lucky to get success by building a product first. The probability of success is a lot higher when you identify the market need first and then co-create a product with your customer.