Let's think about it, we have all adopted to learn the meaning of words through experiences or emotions. We didn't learn each and every word from a dictionary. What if I understand a word slightly differently in my complex mind? Could it result in some sort of pessimistic or optimistic or abstract outcome? And how often is this case true in our society?
Quite certainly this is the case (even if you learn all words from a dictionary), but this is more of a philosophical debate. It is unclear what you are after when referring to 'pessimistic', 'optimistic', or 'abstract' outcomes, but I can point you in the right direction in case you want to read up more on this subject.
One concept that comes to mind from linguistics and philosophy of language is indexicality.
... an indexical behavior or utterance points to (or indicates) some state of affairs. For example, I refers to whoever is speaking; now refers to the time at which that word is uttered; and here refers to the place of utterance.
However, some argue the same holds true for almost any utterance. (Suchman, 1986)
Among philosophers and linguists, the term indexicality typically is used to distinguish those classes of expressions whose meaning is conditional on the situation of their use in this way from those such as, for example, definite noun phrases whose meaning is claimed to be specifiable in objective, or context-independent terms. But the communicative significance of a linguistic expression is always dependent on the circumstances of its use. A formal statement not of what the language means in relation to any context, but of what the language-user means in relation to some particular context, requires a description of the context or situation of the utterance itself. And every utterance's situation comprises an indefinite range of possibly relevant features. Our practical solution to this theoretical problem is not to enumerate some subset of the relevant circumstances—we generally never mention our circumstances as such at all—but to "wave our hand" at the situation, as if we always included in our utterance an implicit ceteris paribus clause and closed with an implicit et cetera clause.
Suchman, L. (1986). Plans and situated actions. New York, Cambridge University.
Much of what we perceive cannot be expressed by language. It's unspeakable. As a consequence, differences in interpretation are very common, especially when it involves complex abstract concepts or highly subjective emotional experiences.
To quote Kim Krizan:
Creation seems to come out of imperfection. It seems to come out of a striving and a frustration. And this is where I think language came from.
I mean, it came from our desire to transcend our isolation and have some sort of connection with one another. And it had to be easy when it was just simple survival. Like, you know, "water." We came up with a sound for that. Or "Saber-toothed tiger right behind you." We came up with a sound for that.
But when it gets really interesting, I think, is when we use that same system of symbols to communicate all the abstract and intangible things that we're experiencing. What is, like, frustration? Or what is anger or love?
When I say "love," the sound comes out of my mouth and it hits the other person's ear, travels through this Byzantine conduit in their brain, you know, through their memories of love or lack of love, and they register what I'm saying and they say yes, they understand.
But how do I know they understand? Because words are inert. They're just symbols. They're dead, you know? And so much of our experience is intangible. So much of what we perceive cannot be expressed. It's unspeakable.
And yet, when we communicate with one another, and we feel that we've connected, and we think that we're understood, I think we have a feeling of almost spiritual communion. And that feeling might be transient, but I think it's what we live for.