that depends on the song, some songs just seem timeless, but they are few and far between. i haven't been writing for 10 years, but its got me thinking about a few of my older tunes (5 years), i guess it would be kind of fun to have a play around with them again. for a start my writing has improved over time and life has changed me a bit so i think i could definately add an extra flavour to some of my stuff, at the end of the day why not? if it doesn't work out then so what!!!