Yes.
Your unconscious mind is extremely observant. It mobilizes a form of attention psychologists call “open monitoring”, which is a diffuse global awareness of evreything in one’s surroundings, as well as internal states. When it picks up on something that merits your conscious attention, it mobilizes a focused “beam” of attention that puts the object of the attention at the forefront of your conscious awareness.
Even when this focused attention is locked onto a target, open monitoring continues in the background. But it can take a stimulus of considerable energy to break that focused attention away from its current target so that the other stimulus gets noticed.
When nothing in the environment is engaging our focus, the spotlight of focused attention gravitates toward thoughts. These can be a target of attention just as any of our sensory stimuli can. When attention is locked onto thought, environmental stimuli have a hard time competing for the focus. There’s a story about Robert Oppenheimer parking at a romantic spot with a date, excusing himself to go for a walk so he could ponder a physics problem, then walking home and going to bed, completely forgetting about the car and his date.
So one key to observation is learning how to release focused attention from a target, so that it becomes more nimble and responsive to signals from open monitoring. In practical terms, this means learning how to disengage from the stream of thought so that you can more fully open up to the environment.
Another factor is letting go of expectations. Expectations of what there is to see have a powerful effect on what we do (and don’t) see. The less we think we already know about a situation, the more open we will be to what is actually there.
Relevant: The invisible gorilla experiment