Although cash is usually seen as the biggest constraint for start-ups, the resource that really matters is time -- not in the sense of whether one has enough hours in the day, but how long it will take to bring a product to market and generate revenue. The time forecasts we make in our business plans are usually way out, that's because, by nature, we're too optimistic about the state of the market we're addressing, or too ambitious in our product development. This leads to big blunders, all of which I have made. With everything taking longer than you would like, you make hurried deals with customers which end up costing money, upset the bank, upset investors, launch things too early, or misapply precious funds to product development, when you might do better to spend money on marketing. I am going to distil My Biggest Blunder: Timescales into a consideration of a 3 x 3 grid, with 'Product' up the y axis, and 'Market' across the x axis. On each scale there will be three values; Current, Emerging and Novel. By picking a cell on the grid, we'll consider what are the challenges of selling a current product in a current market compared with selling, say, a novel product in a novel market, or a current product in an emerging market and so on -- The grid will also give me a structure for relaying the pitfalls of not being self-critical about the state of your product and its market, and the consequent under budgeting of time that results in grey hairs and sleepless nights.