When you talk with a prospective client, you can look at them in 2 ways: Either that every lead is ready, willing, and able, OR that they're not ready, willing, and able.
Having the mindset that they're not a qualified client is a self-preservation tactic. You won't be disappointed when an unpromising lead is actually unpromising. However, you're setting yourself up for failure. You aren't opening yourself up for the opportunities.
Every client you interact with is on a journey to find something that they don't have but need. The faster you identify what they need, the faster you can identify how you can help and present them with options that will best serve them. They might not be on the timeline that you want, but every client is still valuable to have in your pipeline.