Getting a little too ahead of myself perhaps?

On the weekend, had a discussion with a good friend of mine. Both of us expressed an interest in visiting South America at some point in our lives. Volunteering and travelling to be exact, for a good period of time. 6 months perhaps? Said friend fed my excitement about planning said trip, confirming that it would be a cracker of an idea if we both plan together and go together. This was followed by a night of browsing Newtown second hand bookshops and coffee shops with conversation peppered with, "where shall we go?" "when do we go?" "what do we need to do first, second, third...?". 
This, hopefully will be in 18 months time. I have pointed out that it's such a cracker of an idea, that if my friend decides not to come along (lack of funds or change in life direction) that I will be going anyway (however, I will be attempting to rope others into coming for parts of the trip, as travelling alone in South America, being female may not be a completely wise move). 
I am sure I'll be pulled up about trying to make plans 18 months out. Silly things. You'll be green with envy as I am boarding a flight, all cashed up in January 2012. Things like this take lots of planning. And time. And right now, I have time. If I don't plan, the time will pass anyways, and I'll still be 18 months off any sort of trip. Might as well use it wisely?
Firstly. Must learn Spanish. Or start anyways.
Second. Savings plan. Easy as pie (lucky I'm good at this bit).
Third. Keep an eye on said friend and their savings plan and make sure they're as keen as I am and following through.