We’re glad you agree that truth can be known in some areas of life (or have at least agreed to move on to this point). In addition to being knowable, we say that truth is absolute. This means that if something is true, it's true for everyone. There is no such thing as a “personal truth" - something that's only true for you.
For example, no matter what you believe about the danger of being hit by a speeding truck, if you step in front of one, you will get hurt. Truth is based on reality, not our personal opinion of reality. Therefore, it is absolute. Truth applies to all people at all times in all cultures.