The expression don't quit your day job seems to suffice here. Don't quit your day job until your idea has a platform to rest on. You could always work for few years then pursue what you originally planned, just you will have more startup capital which is a plus.
On a side note, if your idea is a tech based startup idea you can save a whole lot of time/work/effort and money if you read up a bit on microservices, docker, coreos, devops, and selling Software as a Service(SaaS).
On a side note, if your idea is a tech based startup idea you can save a whole lot of time/work/effort and money if you read up a bit on microservices, docker, coreos, devops, and selling Software as a Service(SaaS).