I have to be honest here and admit that our LJs, once issued by the hire boatyard, went into a cupboard and came out again when we returned the boat. How many are brave enough to put their hands up and admit the same?? When we bought our own boat, I suppose it was then I became a more responsible being and bought a ‘slimline inflatable type’, as mentioned by MaceSwinger above, and started to wear it. As I get older and more crumbly I realise how vital it is!
I think it is probably different for sailies, in most cruisers you’re cocooned and not as near the water as on a yacht so automatically feel safer, forgetting that you eventually have to move around on deck if you’re going to moor up or whatever.
Something else that Andy (Freedom) mentioned in another post, remember the one hand rule - one hand for the boat and the other for the task. (ie always have one hand firmly gripping a handrail or something else suitable.)