Not at all, because you don’t remember, much less exact data and abstract terms. Yes, if you constantly work with information and read books, understand, act in practice. You will be a good specialist without mnemonics.
Usually a couple of days, a month is enough to leave just a little bit of information in your head, without repetition.
You can repeat the information without memorising it once a week, make a brief outline. That is, to be able to go back later.
Work more often in this direction, sit down more often.
Ultimately I would say it depends on what you’re learning and how relevant it is to your interests. If you’re learning about something you dislike/find boring, then it’ll take longer to memorise.
It also depends on how practical or theoretical the information is. Take physics for example, if I’m trying to memorise a concept, it’ll take me a few cycles. But if I’m learning the syntax of a programming language (without learning any new concepts), then I’ll just need to look at it once then it’s in my head. The difference is, the physics concept is very theoretical (at least for me as I’m not an experimental physicist) whereas the programming syntax is much more applied. Since I’m implementing the syntax much more than I’m making use of the physics concept, I remember it faster.