I'm 68.
It's giving me big problems.
Like many people I moderated the effects of ADHD with heavy exercise (heart rate over 140 for at least 10 minutes), risk taking, and novelty.
At 68 you really are beginning to run out of new things to see and do. Especially when you put it together with the fact that many/most of us are great at pattern matching, we see patterns in everything. So once you've seen one gothic cathedral, you've seen them all, it's very dispiriting.
On the exercise, you just can't do it if your joints are failing you. Being up at 2 in the morning for a 3 mile run on a treadmill just isn't possible as a way to calm the brain any more. I miss that terribly.
On the risk taking I used to jump 7 ft hedges on horses. I now have a 3.9/5 osteoporitic vertebrae in my back and I would be mad to get on a horse again, and no other risk sport that would provide the adrenaline buzz will accept you for training with osteoporosis.
And the longer you live, the longer the list is of the times you've opened your big mouth without being able to hold back your brain and the more things there are in the list to beat yourself up about. That's not fun either.