I'm grateful for being alive now, at this particular point in history.
If I'd been born a hundred years earlier (1850 instead of 1950) I would probably been through at least 1 world war, and possibly 2. I would have grown up in a world where toilets were still very rudimentary and personal hygiene was a very low priority. Doctors were totally ignorant in comparison with those alive today, not to mention that most people couldn't afford to go to a doctor anyway. Also dentistry was still very much in its infancy, so I'd probably have a mouth full of gums instead of clean teeth.
Add to all the above that I could not have been as mobile as I've been throughout my life, as I've owned bicycles, motorbikes, cars, etc since I was around 7 years old. I've also been able to watch international events on a TV screen, that I could not have watched in the 1800s and early 1900s.
I would also have been very poor by now, but thanks to state old age pensions, universal healthcare, and all the other things I've taken for granted throughout my life, such as free universal education, I can sit here at my own computer in my own home, and type this while reading through my bifocal glasses, in a heated room, while watching the cold wet weather outside through draught free double glazed windows.
So I have a lot to be thankful for.