There are people who make a hobby of telling others what they can do and what they can't do. I've learnt to not listen to those people.
Everest is regarded as one of, if not the most challenging of human conquests. I was passionate about climbing and a great believer that one should always challenge their own perception of where their boundaries lie. Everest seemed like an irrational challenge for an Egyptian, so I embraced it wholeheartedly. This feeling grew stronger when I realized that no Egyptian had attempted, let alone stood, on the roof of the world. The desire and pride of representing my country and raising the Egyptian flag on the highest points on earth has been with me ever since.
At the end of the day, people (customers) don't necessarily buy into what you do; they buy into why you do it. People buy Apple because they love the Apple brand - what it stands for - they feel proud to be associated with that brand. What makes Google or Virgin or any of these 'superior' brands what they are is that they have a mission to change the world. Those are the kinds of companies that will endure the test of time.
People tell you keep your job, start the company on the side. If I'm doing it on the side, then probably one of the reasons it fails is because I didn't dedicate enough time to it.
I think that when you start your own business you have to be very clear on what you're passionate about and what your values are. I was very passionate about travel and I wanted to inspire other people. At the same time, I knew if I was going to start my own business, it was going to have to mirror my values, and I knew I was passionate about the environment and about sustainability.
If someone wants to start a business but they don't have an idea that they are specifically passionate about, then it may not be the right time for them to start it. Instead, they should work with someone else who is doing something they care about in the meantime until an idea comes up.