You may be right, particularly about relating to the child.
As for missing out on their lives, the life expectancy of female Canadians is 83 years old. I'd be my parents age when my child was twenty, as my brother soon will be. I might have another 20 years in their adult lives, at least. I have better health indicators than the average person, based on my blood tests, ECG, and liver fat. I eat a lot of fruits and vegetables daily, and I drink a lot of water, almost exclusively. I rarely drink and I don't smoke. My grandparents on my father's side lived into their late 80s and 90s, and they lived in Iran. My maternal grandparents are still alive and well into their 80s. I don't have a family history of heart disease, diabetes, or cancers caused by genetic preconditions (my father's was due to smoking when he was younger). I don't exercise, but if I did pick it up as my mother did, then I could expect to at least meet the life expectancy. Of course, I could adopt and develop cancer the next year. But then so could a 30 year old parent. So, that's why I don't see it as being out of the question. I'd have to see how my prospects were then.