My physics teacher had a saying. Every time we’d ask a question which had many different possible answers, he’d say, “how long is a piece of string?”.

Being good math students at high school, someone eventually realised the length of any piece of string is twice half its length. So from then on, I made sure to answer his question with a smirk and say, “twice the half of it’s length”.

Now when someone asks me how long something will take.

- How long does it take to learn calculus?
- How long does it take to learn linear algebra?
- How long does it take to learn to code?
- How long does it take to learn machine learning/deep learning?
- How long does it take to get a job in data science?
- How long does it take to have a successful online business?
- How long does it take to reach ramen profitability?
- How long does it take to get 6 packs abs?

My first thought to all of these kinds of questions is “how long is a piece of string?”.

My second thought is “I don’t know.”

My third thought is “twice the amount of time it takes you to get halfway.”

By the fourth thought I’m reflecting on my past. Trying to relate the question to how long it took me to do such things.

Then I realise, the simplest (and honest) answer is, it’s going to be different for everyone. And for some things, there is no finish line. When it comes to learning calculus. You could start with the introductory parts and then get as deep as you’d like. And the learning never stops. The more you learn, the more you figure out you don’t know.

I have to remind myself. Every day is day one. And when I’m stuck..., I learn/do the thing to get me unstuck.