Can I actually do it?... Genuine Insight and Perspective needed

Fellow monkeys,
I believe most people on this forum are filled with endless ambition to succeed and make it big (bearing in mind that "making it big means different things to different people)
I am starting my full time IBD analyst gig in London in a couple weeks (think GS, MS, BAML, JPM). However, in addition to my job, I am thinking of writing and publishing a book in the next 12 months.
I am aware of how intense writing and publishing a book on its own can be, let alone doing it in addition to being an analyst at a BB.
My idea of the book is on a current and critical issue and while I could wait until after my analyst gig, that idea might not be so relevant. I am a big fan of Victor Hugo's quote : " No army can stop an idea whose time has come" At the same time, I am have to look at the situation and not jeopardize my job.
Weighing in all the different factor's, what are your thoughts? There is probably no right or wrong answer but the different perspectives might help.

Cheers,