While you might not remember every detail about a certain event, I guarantee someone who was there does remember. Asking family and friends for ideas or details of a certain situation can give you a completely different perspective of the event or time in your life. That perspective might prove to be invaluable in your writing. Be prepared; once you get a group of family and friends together to reminisce, you will be shocked at how quickly the ideas come and how one idea can spark another and another and another.
After considering these factors, the next step is writing a draft. Start by looking through the best autobiography openings you can find and figure out which you can use as a model. Make sure that you write in the first person since that’s what autobiographies are all about. Never switch back to second-person or third-person and be consistent in using the first person point of view throughout the entire content.
Either way, this jump is disturbing, but the description likely caused you to cringe more than the summary. And doesn't some part of you want to know what happened next? Who came to help? How quickly they reached a doctor? If all had turned out well in the jump, you would not have the same compulsion to read on. If you can't think of any details, write a line of summary and return to fill in the details as you remember them. If you remain relaxed about it, you will remember. If you don't, you don't. Writing an autobiography isn't easy, but it should be enjoyable.
"Most people don’t think of spiders when they bite into a tomato, but I do. Growing up in southern Ohio, I spent many summer afternoons picking baskets of tomatoes that would be canned or frozen and preserved for cold winter’s dinners. I loved the results of my labors, but I’ll never forget the sight of the enormous, black and white, scary-looking spiders that lived in the plants and created zigzag designs on their webs. In fact, those spiders, with their artistic web creations, inspired my interest in bugs and shaped my career in science."