I would say you are never too old to follow a dream. My father at 89 with advanced prostate cancer and a bit of a failing memory said he wanted to go on one last cruise. I wasn't at all happy about it, and told him to consult his doctor, who, to her credit, told him if he felt up to it, to go.
We packed his bag for him and confiscated it the night before, so he couldn't fiddle with it, and asked airport staff to put him in a wheelchair, so that we knew he would get on the flight. At 7.00 am the next morning I had a call from the nurse on the ship saying that he had forgotten all his medication. I knew he hadn't, and asked her to search his case, she was really unhappy about it, but said she would ring me the next day if they hadn't turned up, and I heard no further. He got off the ship in Marseilles, missed the coach to take him back on board, and ended up in the local police station, where fortunately one officer spoke English, and understood his 'I need to get back to my boat' as coming from a mad cruise ship passenger (fortunately there was only one ship in port that day!)
We met him off the plane, he was worried about being sprayed for polio on the plane (it was the tail end of the SARS epidemic) and then confessed he had made a lady friend and was worried when she said she was going to come back and live with him!
That was the end of May. In July he had a very mild heart attack, and the appalling ill treatment at the hands of the local hospital led to his very sudden death a few days later, on the morning he was due to be discharged, so he never made his 90th birthday a couple of weeks later.
I am so very glad he had that last experience.