Which chapter you in?

So like, how do you know when it is that a new chapter has unfolded in your life? I mean when you are turning the pages of the metaphorical book of life, how do you know which page has to be marked with a bold typeface proclaiming the chapter number? And it's not like every experience can be penned down in a new chapter...as I can understand, our life plays out itself at regular intervals.. we have more or less the same range of emotions and same kind of experiences with little variations..circumstances change, people change, the places change but the depth of emotions and their effect on us is what changes. Moreover, it could be a sub-plot or a link in the chain of events that started long ago. And, even as you are in the midst of an unfinished chapter, some one some where might involve you in their plans and a whole new (parallel) chapter might get started unbestknown to you!! (and when you are the one actually involved in those plans, it might be reduced to a mere anecdote or a subplot in your book)... I mean, you only know when you look back in time and say.."i guess it was that moment that changed the things to come..." and obviously so, because though its your life being played out here and you get to be the centre of it all, more often than not, the locus of control is entirely external... So, if we cannot exactly tell which chapter the present is going to end up in, I guess we should all know it at a later stage thus ending up a chapter short at the end of time ;) better still, if you can have someone who can end up that last chapter :P