You cannot miss an opportunity you were not able to define or recognize

An opportunity presents itself, you never chase it. If you have to chase it, the window has already been closed.

If you only recognize the opportunity by its outcome, then the opportunity has already gone, and it never was an opportunity for you in the first place.

Therefore, don't beat yourself up for "having missed an opportunity" unless you clearly saw it, acknowledged it, and didn't do anything about it. This is the only time where you "missed an opportunity."

It's like someone knocks at your door and leaves a bag full of trash. You yelled at them to get the bag out of your doorstep. Later on, you learn that there was a gold ingot inside. How could you have known? You couldn't, so no point in being frustrated.