The part that is more false than true is in the first half of the quote.
You won’t always know if they like you. Some people are very good at hiding their feelings even when they may be incredibly profound or intense for someone else.
Oftentimes, this is out of fear of being found out, as well as the fear that those feelings may not be mutual.
The second half of the quote is a little bit more nuanced.
This is when you are dealing with someone who seemingly doesn’t like you.
In this particular scenario, the sense of confusion that may come out of that would only be because you were already assuming that the person liked you in the first place.
In other words, you may have allowed your desire for this person to make you believe that there were signs of interest being exhibited towards you when in fact there weren’t.
This is where your desire and consequent imagination can really cloud your judgment.
For example, you may look at the fact that the person looked at you briefly today as a sign that they like you, when in fact you were only one of many people that they looked at today.
You may look at the person walking by you as a sign that they were trying to get your attention when in fact, all they were doing was trying to take a shortcut to their destination.
Hence, the confusion that you may experience when this person seemingly doesn’t like you may have everything to do with how you made yourself believe that this person must like you than with the true reality about how this person actually feels towards you.