Bilingualism may reduce your risk of dementia. But many of us have the experience of failing in language learning in school, but it is a mistake to interpret that failure as an inability to master a new language. In his TED talk, Benny Lewis makes the case that you can learn a new language.
Tim Ferris has some rather nifty hacks for language acquisition:
http://www.fourhourworkweek.com/blog/2009/01/20/learning-language/
Thanks Tony, always good to hear from you!