What a load of bollocks.
Knowing how to do certain things or aquiring certain possessions in no way makes you a 'grown up'. Being a reliable, mature, level-headed responsible person makes you an adult.
I've known people who've done a lot of things on that list but are still in no way mature adults.
Also... 'Always going out with a sensible pair of shoes'? If thats an indicator of being a proper adult, I will never be growing up. Five inch heels are constantly needed when you're only 5'4"!
Edited to say: I've just had a good long look through that list, and I meet a lot of those requirements. I still don't think I'd class myself as a proper adult though. I'm totally lost with life, and I'll freely admit that.