The best note-taking app for me would be like if I was paying a really smart person so that (i) I could tell them at any time of the day some info or thought I'd like to use later somehow, (ii) I could make queries of any format later about the data I entered.

The key thing is that I don't want to have to decide in advance how I want to use the information. I just want to store the information that I know it might be useful or important later.

(More concretely, I could see this being a single huge text file in which I can make natural language queries; each query generates a view of the file that corresponds to selected sentences in the file that match the query. For example, if I asked "what are the things I have to do for next month", then it would show me the sentences that correspond to things I have to do for next month. If I queried "exciting ML papers", then it would show me the sentences in which I link or talk about an ML paper, and I sounded excited about it.)

It would be cool if raw text could be parsed into structured data. Something like "Yesterday at 6pm, I took a flight from MIA to LAX airport on Delta" could be parsed into:

  {
    "date": "2020-10-09T06:00:00-0800",
    "action": "flight",
    "destination": {
      "iataCode": "LAX",
      "name": "Los Angeles International Airport"
    },
    "origin": {
      "iataCode": "MIA",
      "name": "Miami International Airport"
    },
    "airline": {
      "iataCode": "DL",
      "name": "Delta",
      "url": "https://www.delta.com"
    }
  }

even better would be to parse it into schema.org entities

How would you use this information?

i would like to be able to search it by attribute, like "find me all flights I took on Delta" or "How many flights did I take to Miami last year"