Being young definitely helped her I think. She's also just such an adaptable cat. She's adapted fine to moving the litter box, new sort of litter, different food, learnt to scratch a scratcher rather than the couch within days... I think we just got lucky!
We tried putting a harness on our Siamese years and years ago when she was young - the breeder told us they liked going for walks, but she just froze in one spot and refused to move
And my husband actually thinks it's really cool! It didn't take him long to realise she was walking him rather than the other way around, but in saying that, when we decided to go back inside, we walked back toward our door and she trotted after us happily, and went straight inside the house without any fuss!