Oooh I like this topic
I like to think of it as a business plan, for anyone who has run a business will tell you that the biggest joke about business is a business plan because it never turns out as you predict. I have been in business and it was the right thing for me to do at the time but the endings of that stage of my life ended naturally for now at least.
But when you right a business plan (I am sorry to go all corperate here... I hate corporate

) you asses the market conditions and your current ability to offer to the market/community lets just say client base (ouch more corporate (Shudders)) the goods or services you are going to provide, so you research the enviroment you want to go into. But then you have to research yourself as well through means of a swot analysis which is basically your strengths weaknesses oppertunities and threats. Essentially you map out cirtain goals and criteria for a cirtain time frame which sets you up for when your business starts trading.
Now your overall intent would probably stay reasonably constant throughout the lifespan of that business which is basically to make money. But the barriers and pitfalls are different, some you can predict some you cant. But if you work enough at it and it is the right thing for you, you will get there in the end. Looking back on my time running a business I can now see several other oppertunities which I could have taken at the time but didnt because I am now looking back with perfect vision so to speak.
So think of it then as before you come to earth you asses your enviroment, what position are you in to offer to something to humanity as a whole (as I believe we all do, even if it is something seemingly insignificant) and what is the best place to be in for you to achieve your life goals. Hence you choose your parents etc.
Now as you travel through there are oppertunities for you to grow and learn throughout, if you are supposed to meet someone and achieve something, for example a spouse, business partner, friend whatever and you miss that oppertunity, it will come round again, and again. Have you ever noticed in life those situations that are always there and you cannot seem to get rid of them until you have done something about it.
Essentially then, the life plan is not fixed, its flexible.
I like to think of it like the doctor who theory of time (Yeah Im a sci fi nerd too

lol) where time is in constant flux, you can travel back to 1982 for example and monsters from space can invade and the world can end there and then. (Hence the reason for the doctor being there to save the earth again) but there are some instances he cannot do anything because those events have to happen because there is a rippling effect through time and space, for example if he finds someone is going to die, but that death will inspire someone to create the first manned mission to mars for example. Then he cant to anything about it.
So in general, the human existence then on earth is in flux and anything can happen. But there are those events that have to happen for you to move forward perhaps. If you dont meet that spouse, business partner, friend, there are certain goals you cant achieve. But the moment is not set. For example if I miss oppertunity number one then oppertunity number two comes a year later. I think thats where the guidence comes in. But these experiences will feel right, because we have used our free will to plan them in the first place. Something inside kinda clicks and you think Why not? I think we all can relate to that.
One thing I always do when I am looking for something, I am normally a very untidy person but in an organised way. (Gemini trate apparently) is get frustrated when I cannot find something and have looked everywhere except the one place where it supposed to live. Or have put it safe for some reason Its blindingly obvious where it is lol. When I find I have put it away or in that safe place I say outloud "Well done past Jez" example, I have been looking for a newspaper clipping that my father gave me from when I won an award for a series of art works years ago, which he wants back because I have now scanned myself a copy, I finally found it today in with my script that I did for uni, because I know that is one of the things I always keep safe as it is very important to me "Well done past Jez". When we have these fixed events in our lives, we say the same thing in a way because subconciously we know that we wanted them to happen
Right thats enough random thoughts from me for the evening.
Peace Love and Freedom
Jez