If I quit my current job and choose to the job that I want which likely earn bigger in the future, if I didn't make it, I will regret, at the same time I can't back to my old comfort job. Don't say take two jobs at the same time because the first job requires me to work for full time.
Apart from the risk associated with the uncertainties that comes with retiring early, after retirement, it is always as though the next point is death of you don't make proper plan for what productive activity you should be doing after retiring. for me, i don't make a big deal out of early retirement because in the process of working, i get to become really engaged which makes life less boring. it is not as though it is a bad thing to set early retirement plan most especially knowing that you won't always be as strong and relevant as you are at your prime. you should do it but that should not be the whole essence of life. while still working, you could invest into an asset that will serve as your retirement plan or some sort of a budgeted amount for our luxury if you so desire.