Relationships: How are your relationships with your family and friends? Can they withstand the heavy time commitment required with Ironman training? Will your bike see more action than your bed? Do you only socialize with triathletes or do you have a healthy balance of different friendships?
Preparation: Would a year of racing focused on shorter faster distances help set you up better for Ironman success? Maybe you need to shake off some of the heavy endurance muscles and tap into speed in your legs that may have been beat down from years of long-distance training.
Health: Have you had your blood tested recently to make sure you are not deficient in essential minerals? Women specifically, have you had your feritin tested? Are you in optimal health?
Goals: Are you trying to qualify for Kona? Make sure you pick a race based on your strengths so that you can optimize your chances of qualifying in your age group.
PR: Are you trying to PR on a favorite course? If so, have you adjusted your training plan? You can't expect different results if you are training the same.
Support System: Have you considered signing up for a race with a group of people? Training buddies are great support on for a journey like this? It could be a great opportunity to meet new people or build bonds with triathletes you already know.
Family: Are you turning this trip into a family vacation? If so, does it meet the needs of those in your family or is it purely selfish? Did you do the same "family" trip last year?
Answers to these questions are, of course, subjective. Perhaps you really only need to ask one: Are you ready to do an Ironman triathlon?Ironman event.