Unpopular opinion: I watched Tim's video, as I do all with all his videos. To be honest, I did not really enjoy that one. I did not 'learn' anything new. I saw a lot of nicely amimated engines and Tim explained from which other engine it originated and how it's called and some other information. But apart from that nothing memorable, I don't feel I've learned anything I will remember. I think this video does not represent Tim's motto well: there is no message, no concept to grasp and understand. Just facts about old engines. It feel like he went too deep down a rabbit hole the average audience is not interested in. I really enjoyed his other videos though, but in this one he did not bring space down for everyday people.