Ah, the mystery we call life. What is our individual path, our unique journey ? How do we know which door opens to our future?
I believe that our life's journey is not carved in stone. T here may not be one door which is destined to be our portal to the future.
As with the findings of quantum physics, probabilities exist, possibilities as well. It is only when an observation is made, a choice is arrived at, does a door open and a path appear. There may very well be a multi-universe which erupts into existence which each possible choice.
In the case of human behavior, it is our choices when set us upon one particular path as opposed to another. Presumably, this is based upon our desires, interests and talents.
But what happens when the door we choose to knock on doesn't open? Do we persevere? Do w stand and pound on it ? Do we ever walk away?
Of course every case as every life is unique. Some of us are extremely determined to seek our desired goal and will not take a closed door to convince us to give up or try another one.
Others are more flexible, less dogmatic, less determined. If one door seems closed to us, we may move to another. If that one opens, we will enter and see where it leads us.
There is no right or wrong approach which applies to everyone. I do believe, however, that knocking continuously without any response should alert us to the possibility that this is not a reasonable choice.
Our goal in life should be to find some degree of peace/serenity or even happiness with our life's chosen path. Continuously facing a closed door will not promote such serenity. Circumstances outside any of our personal control can have an enormous impact on the entire scenario.
But it makes sense to follow the path that opens up to us. Sometimes we need to embrace the opportunities that arise before us, even if they weren't those we dreamed about. Keep vigilant, alert and aware. Opportunities can arise and fall away if we are not ready to react.
Perhaps the "universe" knows more than we realize which door will lead to our future. But ultimately we make the choice and the effort to turn the knob, open the door and enter.