If. When. Before. Prepositions describe relationships between other words. When alone, words like "if " or "when" or "before"  are rather meaningless and hard to define. Not unlike us. Put these words in a relationship and the possibilities are somewhat infinite. Not unlike us.
The preposition of the day is if.  Only if.  What if? Or sometimes just if.
If...
"The Next Three Days" starring Russel Crow had not asked the question "Just how much in control of our lives are we really?" then I wouldn't be writing. If two days ago my brother had not chosen to ignore his diabetic orders and control his life with alcohol.  If one day ago she had not said he had to quit drinking. If today the ambulance had not come for him. If today my niece would not have had to sign a DNR order for her one month old child. If I was in control.  Because I am not.