Let's take a simple example: you had an important meeting at 9 am but since you were stuck in traffic, you were late by 10 mins.
The final outcome can be clearly explained by actions that directly or indirectly led to them. May be there was an accident causing the traffic jam. May be you woke up 10 mins late than usual thereby getting caught in rush hour traffic. May be the cab you took to work, arrived late at your destination cause he woke up late.
All of the above are totally controllable actions, albeit not in your direct control. Hence the feeling that life is random. Because none of us have any control over the outcomes of the actions of others, who subtly influence our lives on a daily basis.
Think of it this way: our life is intertwined with the lives of others in one way or the other. From the cab driver who drives us to work to our loved ones who shatter our hearts, their actions influence us, some more than the others, but influence us nonetheless.
It's a complex equation, with a whole lot of variables, most of which are beyond our control and unknown and the solution to this equation is the outcome of an event.
I believe that if one knew the values to all the variables at any given point of time, then one would be able to solve the equation with precision