There is quite a big difference from taking choices and giving advice from the outside of something and from the inside.

When you’re inside we are often moved by ego, ego controls us and makes us stupid.
We are less objective and more subjective.

Which is the exact reason why we aren’t often able to do lifechanging choices.

That said, it’s also hard to avoid pinpointing the “I told you so”, when something happens. It’s easy to feel like this would be useful, but it’s not.