What if I am just imagining the high pitch sound in my mind whenever I hear about or think of tinnitus just like how someone tells you to imagine a whale and you form a mental image of a whale? I don’t pay attention to the noise while I’m busy doing stuff but once I think about it, it is as hard to stop noticing it similar to being told to breathe manually, and it gets very annoying after some time. Is it what tinnitus really is?
Brains filter out all kids of constant things when focused on something else, like how minor pain can be ignored for periods of time when distracted.
If you only seem to have tinnitus when you actively think about it, possibly due to someone else talking about theirs, then it could be your imagination.
If you notice it occasionally, like when the room is quiet and you are not actively thinking about having tinnitus , then it is tinnitus. There is an extremely wide spectrum of how quiet/loud it is, whether it happens all the time or only sometimes, and whether it is consistently the same or varies. I have it but only notice it occasionally and mostly when I have some ear pressure. Mine sounds like a mosquito or a failing old tube TV when it is noticeable.
Your description of it sticking around once you notice makes it sound like you do have tinnitus, but a mild case.