It's currently a major area of research and an unsolved problem to find out what individual weights do – and the most recent research seems to suggest that there is not a one-to-one relationship between ideas and weights. In fact, one line of research is showing that each weight encodes multiple ideas with what is called polysemanticity [1], while another line of research seems to show that individual factoids are spread across thousands of weights and possibly even multiple layers [2].
[1]: https://transformer-circuits.pub/2022/toy_model/index.html [2]: https://rome.baulab.info/