We all know there's a difference between 'knowing' and 'experiencing' and people can be at various stages of each - I will try to tease out the difference here and apply it to Buddhist awakening.
Knowing is intellectual and is always knowing "about" - it is second-hand and all about theories of something.
Experiencing by contrast merges the 'knower and known' into one and at this point one gets to understand directly. Experiencing does not require one to have theories 'about' the subject one understands and is experiential and direct.
For instance, Professor D.T. Suzuki (鈴木 大拙 貞太郎) was a great Buddhist scholar who was instrumental in spreading Zen to the West and a prolific translator of Chinese, Japanese, and Sanskrit literature but he was not enlightened and had no enlightenment experiences. Suzuki knew a lot about enlightenment, but never got to understand and experience it himself directly. There is also always the possibility for someone to not even know about enlightenment even in theory.
So, it is possible not to know or experience/ understand, but it is possible to know but not understand, and also it is possible to experience but not know.
Buddhism is about knowing and understanding, but it's about a strange kind of paradoxical knowing since any theory about it has to account for it being subjective and unique to each person. The experience of knowing about enlightenment is what Neitzsche described as becoming "a new beginning, a game, a self-propelled wheel, a first movement, a sacred 'Yes'" and when you finally understand you do not become someone or something else, but become who you really are which seems a bit paradoxical as who else could one be? In a nutshell enlightenment means going beyond knowing about buddhism, and puting into practice Buddha's teaching about becoming who one is - it is about understanding, finally, oneself!