How can we make it remember what I taught it before

Hello,
I am using ChatGPT instead of search to not waste my time flicking though the mass of newbie and irrelevant information that’s flooding the internet.
(I am a senior IT Pro, AI classes @M.I.T. in 88;-)

However, what annoys me is that it does not remember things.
I 've been recommend to to upload previous chats.
However, the results are disappointing. I get a lof of yeah and sure, but no real effect!

I have the goal to train an AI to the level of TARS. But this is definitely not there yet.

Is there a more efficient way to keep trained context than import export of text files?
any other suggestions?