Sensing someone who is not visible is read as intuition, unprocessed emotion, or the memory of someone missed. Dream books see it as awareness that runs ahead of understanding.
Where in your waking life have you met something like this lately?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.