I am going to post a controversial opinion, so stop reading if you are easily offended.
I agree it is fantastic he raised so much money, but I hesitate to go as far as calling him a hero. He walked round his garden, which is not really a difficult thing to do if you can walk, and the risk is minimal given that any poblems, you take a break and go indoors. The reason he has raised so much money is purely because of his age. If someone half his age decided to walk round their garden 100 times and asked for donations, would they raise £26 million? Somehow I doubt it. If I decided to climb all the Munros of Scotland without the aid of motorised transport, I very much doubt I would raise that much money, even though there is a significant chance I would die trying.
My hope is that this is not going to be used as another stick to beat young people with (an insidious hobby in the UK). It is the younger generations that are currently taking risks with their own health doing the essential jobs to keep us going and get us through this mess, and it would be incredible hypocrisy if people who applaud the NHS on Thursday evening then turn round and say young people are lazy and useless, look what this centarian did, without any thought as to the primary reason why it has received so much global attention.