वेदाहं समतीतानि वर्तमानानि चार्जुन।भविष्याणि च भूतानि मां तु वेद न कश्चन॥
vedāhaṃ samatītāni vartamānāni cārjunabhaviṣyāṇi ca bhūtāni māṃ tu veda na kaścana
Word by word
The verse says
I know all beings — those gone, those here now, those still to come. But nobody knows me.
In plain words
Two halves, and the second is unusually bare.
He knows everyone, in all three directions of time.
Then: māṃ tu veda na kaścana — but me, nobody knows. No exceptions offered.
Where you've felt this · at work
The woman who has run the canteen in an office for thirty years knows every person in that building. Who takes sugar. Whose father is unwell. Who has been quietly applying elsewhere. She knows it because people talk while they wait for their change. Almost nobody in the building could tell you her surname.
Going deeper
The asymmetry is the point, and it is not a boast.
Being known and being a knower are different positions and they do not swap over easily. Everything on the first list — past, present and future beings — is an object, something that can be looked at. Whatever is doing the looking never appears in the field of view. You cannot see your own seeing.
This is why the chapter has been pressing so hard on the difference between knowing about and knowing. Facts travel in one direction here. You can gather information about God the way you gather it about anyone, and your position stays exactly where it was.
For a reader that is a relief of sorts. If nobody knows him by investigation, then not having worked it out is not a personal failure. What the chapter offers instead is not a cleverer method.