24/7 ? I beg to differ.
There's a bit of a lull in the wee small hours.
If you get the City Flyer you can skip all the outer London stuff.
I (not so) fondly recall the occasion when I'd come down from Oxenholme to Milton Keynes, caught the Virgin bus to EGGW and then got on the shuttle for Luton Airport Parkway. I got on the first available Thameslink on the principle that they all stop at Harpenden and then watched as we whizzed through every single stop until we got to King's Cross (albeit quickly).
That 'Central' tag on the Hendon station does rahter look as though Stelios is trying to imply that Hendon is not in the wilds of North London.
You could now take Thameslink from London King's Cross to Luton Airport Parkway, shuttle to the airport, Virgin bus to Milton Keynes (two quid single, bargain !) and then take Easybus to Hendon. You'd need a really good reason though.