Before you actually decide to retire early, it's probably better to test-run and mimic that new lifestyle as well as possible and find out if there are any flaws in your early retirement plan.
Create a retirement budget with all your expected needs and expenses. Also, take into account that new fiscal policies may apply if you retire and at what age. This may seriously impact the financial space you have with a given budget.
Make up your mind and what you expect to buy, need, and have expenses, and list them all for making that new early retirement budget. Next start living according to this budget for a while.
Maybe you left things out you thought you wouldn't miss but want to have after all. Or you feel there's not enough space for unexpected expenses like car repair or medical costs. Realize also that with age, medical costs will likely increase.
If you succeed living within this what-if retirement budget for a while under different circumstances, then you will have a good indication of how successful your early retirement plan will work out.