I just watched this on Youtube also (thanks to Ancientsgate pointing it out to me) and had so many good 'feels' from it. I really liked they way the show allowed Martin go on his ancestor search without too much intrusion from the folks behind the scenes who put the show together. So, being allowed into his home and the home of his brother and then going all around England with him was an almost intimate experience. Kind of like, just me and Martin walking around together. Also, his look, gait, voice, clothes, and age appearance were all very 'John Watson'. So, not only was I walking all over England with Martin, it also felt like I was going around with John. It was very nice to feel back in touch with my favorite actor during this long hiatus.
I could fully relate to his feelings about his grandfather at Dunkirk. I just found out my great great grandfather was killed at Gettysburg on the first day of fighting. We recently visited Gettysburg and I found his name on the Pennsylvania Monument. There is something very moving about seeing it 'carved in stone'.
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And I said "dangerous" and here you are.
You. It's always you. John Watson, you keep me right.