Calculating and being prepared is critical. My work life is about managing expectations and delivering on my word, oh and marketing, marketing, marketing. There's really no point in doing anything if you don't have a marketing strategy. You can change it as the days go by but you must have some kind of a plan in place at the get go. Think of it as having an itinerary and road map you create before heading out on a journey through territories unknown. Wouldn't you do a little research? Wouldn't you make some sort of financial plan and calculate exactly how much time and money you need? Wouldn't you do whatever it takes to be prepared so you have a fun, safe, trek and arrive safely at your destination?