That's fair.
I'm very aware that some of those things - like seeing penguins in their natural habitat - may not happen (or at least may be extremely difficult to pull off). But I'm completely confident that others - like dog sledding or swimming with the dolphins - will absolutely occur.
As I read the list I also thought about more experiences I'd like to have. I'm now to over 50 on the list but I figure that will give me some wiggle room in case some can't be arranged. My new additions:
46. Ride a bike
47. Hike Diamond Head
48. Watch a bear catch a salmon
49. See the Grand Canyon
50. Go to the ballet
51. Learn karate
52. Ride in a pedicab
53. Jump on a trampoline
Even started looking at bikes, just in case. Isn't she pretty? If I ever own a bike I want it to look like this.