As others have said, 55 is by no means too old to learn.
There's an airfield just down the road from you, at Kerikeri. There are two flight schools there - pop in and have a chat and see how you get on with them.
Some things can be a bit trickier to pick-up as you get older, such as in my case gettting the hand/eye/foot etc co-ordination for the landing (think back to when you learnt to drive - the clutch/gear/steering/braking co-ordination needed to turn without thinking about it) and you'll get the point. And expect it to be challenging in unexpected ways and to pick up a few skills and lots of intersting knowledge on the way that maybe you hadn't thought of, such as some of the theory stuff.
But go for it starting with a trial flight if you haven't already done this. And if you get motion sickness on the trial flight - that's just another bit of the challenge!
I'm 52,started learning a year and a half ago,away a lot (Merchant Seamen),so always going over stuff that i forgot when back home,anyway hope to take skills test Monday after 60 odd hours...So go for it!!!
I'm still trying to work out how Keef knows your location from the information provided, but I know he has a friend in a high place. I remember Paihia, not sure if I've been to Kerikeri.
Nah. My experience almost exactly mirrors that of Jim. As has been previously stated, the book larnin is the hardest part (with respect to getting an ageing noggin around the concept of understanding completely new stuff) but the general excitement of the whole process helps overcome that.
Your natural aptitude will determine how the whole process goes, not your age.