sweeter wines appeal to younger palates. i think as palates age they tend to prefer more savoury, less sweet foods and drinks. my first wines were things like Mateus and local Gewurz/Muller Thurgau blends. these wines were drinkable, and introduced me to some of the flavours of wine. but it was a delicious Austrian riesling that someone brought back from Europe that made me realise wine could be an experience -- it filled the whole of my mouth and the back of my throat. aahh -- the good old days of added anti-freeze.
soon i graduated onto the pinotage and cabernet that grew at the vineyard across the road (i must have been all of 14!). my parents started buying juicy Australian red wines -- again quite sweet. when i had a scholarship i could afford the occasional experimental bottle from Europe, which introduced me to interesting flavours and textures. but there were a couple of aged reds that again revealed the potential experience of wine -- a Chateau Margaux (i forget the year) and a St Nesbit (a tiny claret-producing winery from South Auckland).
i think if i'd started off with the Margaux i wouldn't be able to drink anything but $300 bottles of Bordeaux classed growths and most of the world's wines would be a disappointment.