Many first time entrepreneurs we fund at Series A think the fund raising process in Series B/C maybe somewhat similar to Series A where the entrepreneur meets the VC a few times, the VC does their diligence and issues a term sheet in a few weeks.  Many times the process doesn't play out like this. The Series B/C process can be lot more involved where the Growth investor wants to see traction on many business metrics, comfort around the capital needed to get to profitability, a fully built out management team, a functional product with revenues, etc, etc.  And surprisingly there is very little co-relation with the amount of capital being raised and the intensity and lenght of the process.  This can sometimes throw  the entrepreneurs into a spin as they have not budgeted  enough time for their next round and they end up with a bridge round before the next financing which is always a very tricky position to be in. It is therefore important that the capital being raised in Series A is sufficient enough to get an entrepreneur to a point where some of the product, team and market risks are mitigated to enable an effective future fund raise, even if it means raising slightly more early on. And the entrepreneur should also be paranoid about spending the Series A monies raised effectively (ie it is better to spend monies on demonstrating early traction on a product even if it is not fully built out rather than building all the bells and whistles on the product at the cost of showing early traction).

Capital raising is an art and a science and entrepreneurs need to understand and master that skill along with the zillion other things on their plate.  I have seen situations where very strong entrepreneurs have lost out to their weaker counterparts who have been better fund raisers than them.