OK - I’m off! HI Rajaraman - we’ve both been there, right? It’s somehow better, but not easier.
In my experience, there wasn’t one thing, it was often a case of keeping lots of plates spinning. Clearly one of the big challenges early on is making sure you have enough money to get to the next stage. It always takes longer and costs more than you think. Running out of money (and we did that, twice) is hard and hugely distracting.
But money aside, our main mission was simply to find product market fit as soon as possible and then prove that by having paying customers. Prior to that, all your conversations with investors and even staff, are a little bit hypothetical, but once you have some real customers willing to give you money (Jason Lemkin says at least 10), then you start having some data that backs up your hypothesis.
So, I would say, certainly in the early days, if you can manage your cash and focus on proving product market fit then you’re in a much stronger position.