What helped you make the decision? Did you already have a running business before leaving or just had an idea or left your job and started searching for something to work on?
I started working with my co-founders on nights/weekends while still working full time. We got a working MVP and our initial pilot customers (very low revenue).
We each calculated how many months we could go with "no pay" until such time as either we would need an investment or close the company. We used this information to create a drop-dead date by when this decision would have to be made.
Then we each implemented our individual transition plan. Mine was a 3 month transition plan. I first went part-time (20 hrs a week) with my current company for 2 months. Then I went to 8 hours a week (as needed) for the remaining month. Then I transitioned out fully.
What worked for all our co-founders is that we all agreed to honor each person's individual transition plan. Each of us put in a full week even if we also worked somewhere else. It was rough to be working two jobs simultaneously for awhile but we had a clear timeline and we were honest/open with each other.
This worked out well as it helps us all set very clear goals and deadlines for the company as a whole rather than just working without a plan. As we neared the drop-dead date we were able to bring in investment. We are a year out from that initial transition period and we know have closed a seed round and have ~8 employees. Planning, honest and clear communication worked for us.
I started creating multiple streams of income so as not to be 100% reliant on any single one.
I created a few additional income sources and analysed the best performing in terms of income per hour- I wanted to free up as much time as possible, so I was looking for those with the highest remuneration with as smallest time commitment.
Unsurprisingly, I realised that even my very well paid full time job was insignificant in comparison to other opportunities that you can create yourself, like teaching/private consulting. This assumes you have a field of expertise that others will pay to leverage.
I now work full time on my company, innerAthlete (innerathletenutrition.com coming this week), while doing some teaching, workshops, and private Product Management consulting.
You don't know there is a business 100% before you start full time. Personally, I quit all jobs before there was even a product. It might not be the best for all though.
I think there are four-five ways:
1) Raise a small amount of money from friends and family & yourself and drop all your cost to minumum - maybe move in with your Co-Founder(s).
2) Get a part time consulting gig and move in with your parents.
3) Start small part time and apply to an accelerator and get the first 50-100k to start 100%
4) If you have a high salary consider to hire 1-2 persons overseas for 700 USD each via Upwork or Fiver to do the initial work for you. Also, get some part time interns.
(I dont recommend #5)
5) Work slowly alone over years part time to either succeed or, more likely, die because you never get really started.
Hubris, magical thinking and stupidity.
"Only an unreasonable man looks at the world and believes he can change it. Thank God for unreasonable men"
Steve really nailed it.
I didn't plan to start a business, I didn't go around asking people for money, or any of that. I was working for yet another slightly shady software development house, watching them give clients horrible customer service, viewing every customer ask as a revenue opportunity, and sitting on customer calls and finding myself agreeing with the customer about how badly we sucked.
I moved from operations to sales, as I couldn't take any more of the operations manager, sold 1/4 million my first month and was let go because they didn't want to pay the commissions.
At that point I said to myself that's it, I am done with this, I am not doing this again I'd rather starve on my own than suffer through this again.
Almost seven years later, I am successful, happy, and will run my own show until I retire. Doing it myself it hardly qualifies as working, as I really enjoy it. My only regret is I didn't do this years ago.
Is it easy? No. The first few years I had no life, little money, and worked insane hours. The stress those first five or six months was intense. I now look forward to Monday.
"Pointy-haired Bosses" (think Dilbert) and RIFs. I did have side work that I was able to expand.