We did, indeed, figure out that we were probably both at Watford Town Hall in '74.
Another connection - I was also meant support some variant of Here & Now in Leeds in about '82 but was in hospital so couldn't make it! I sort of drifted away from stuff like Hawkwind, Amon Duul, Fairies etc. for a while, but decided, as I got older, that I didn't care whether they were 'good' or not, I still liked them. Hannah, my daughter, used to dance around the room to the loud bits from 'Hall of the Mountain Grill' when she was two or three. She recognised the songs when we went to see them live when she was eight.
Sort of getting back to the topic, one of this things in the documentary which seemed very very true was that seeing Hawkwind, as opposed to seeing Yes for example, was that you thought 'hey ho - I can play Master of the Universe - let's go', the fiddly bit at the start of 'Roundabout' is rather harder. So, like punk, I reckon Hawkwind must have encouraged lots of people to actually play instead of listen or just walk round with album covers under their arms.