One way to think about it is - Tech is just a tool. Tools are used to serve some Purpose or Need of yours. That can become your compass.

So if someone wanted to build a chair from wood, they would go learn how to use a saw. But as you observed, these days there are hundred of ways to build the chair. Maybe with hammer and nails, maybe with 3D printers, maybe with genetic engineering - design a seed plant it into the ground and it grows into a chair.

But all these are just tools. The original Need - a Chair. Once that need is satisfied, you can walk away from the shed and all the ever growing number of tools inside it.

>When you intend to learn something new, what would be main reason?

Curiosity and necessity. I nurture the wisdom to know the difference, and the ruthlessness to act accordingly.

Like everything in life: need first, want second.

Curiosity.