I had my 40th in Arillas last July and it was just the most perfect birthday ever! Spent the day on the beach, just chilling, lovely meal and a few drinks in the evening, spent with my two children - absolute bliss!
I hated turning 30, it really freaked me out but I love being in my 40's - can honestly say have never been happier.
As for feeling 40 - I still feel like a kid inside, often wonder what I'm going to be 'when I grow up' and my kids are always saying "Oh mum, when are you going to grow up?" My answer - NEVER! As soon as you stop feeling the magic of a child, you must wither and die surely!
Have you any grey hairs yet Joe? That's a bit of a shock to the system but that's what hair dye's for!!