When you spend time shamanic journeying or astral projecting into the "Otherworld", you realize that there are many "senses" available to a human consciousness. There are five physical senses, with which we interact with the so-called material world. We also have inner versions of these five senses which are able to receive impressions from the spiritual realms, inner projections, and dreams.
There is another sense we need to talk about, "intuition". Intuition is a sense, like your hearing. It is the telephone line through which messages come from spirit. If your ancestors, spiritual guardians or helpers think you need to know something, they will send the message through intuition.
It is key then to take your intuition seriously. Stop thinking it is "just your imagination". Sure, try to validate things through observation and reason. However, take your intuition just as seriously as your sense of reason and the sense data your receive about the material world.
When you start listening to your intuition, you will receive more and more messages through it. It's like finally answering that ringing telephone, now that the spirits have got you "on the line" they are going to keep speaking all night long!