I’ve missed all the baby steps, and this giant leap just seems… weird. No other word for it, really. Last time I saw Bloc Party they’d not released Silent Alarm, their superbly acclaimed debut album. They were playing the Buffalo Bar, Islington, with Youthmovies in support, and Ship’s A Going Down I think. I was DJing between bands. It might’ve been Pretty Girls Make Graves before Bloc Party took the stage – I’d read that they were fans.

It really doesn’t feel that long ago – I remember the taxi ride home, back to the first place I rented with my now fiancée. Must’ve been, what, four years ago? Maybe. I was living off Crouch Hill, in a nice one-bedroom ground-floor place. Big garden. Dodgy carpet in the living room. Like yesterday.

So stepping into Alexandra Palace – just up the road, really, from that flat and the one I moved to after it – to see Kele Okereke’s face super-big on side-of-stage screens the size of battleships is, to say the least, something of a wake-up. This band went and worked themselves into A Big Deal while I was hiding myself away in basement venues, eager ears on the lookout for something New and Exciting, as Bloc Party had been back when. There’s beer flying about the place, odd-looking couples arguing with one another, teenagers at their first or, maybe, second show. All people from all places now get Bloc Party; they’ve bought the billboards and now you can buy the t-shirts… what looks like hundreds of them.

The sharp, angular riffs echo about this cavernous hall in a discomfortingly distant manner; engagement’s limited, obviously, but Okereke nevertheless attempts to converse with the thousands before him, an endearing smile perched below his sparkling eyes throughout the evening. The punch of songs like ‘The Prayer’ and ‘Like Eating Glass’ is lost in Ally Pally, but that’s to be expected: never could these four men have dreamed, until incredibly recently, of performing them in such a space, even when they were cavorting with Jools Holland and Glastonbury crowds. Their music was never meant for mass consumption; it’s too personal, too ingrained with soul to loiter with chart-bothering indie oiks like Kasabian and company – they should be here, no doubt. But Bloc Party?

Yes, surprisingly, and it takes a maligned single to prove as much. ‘Flux’, tonight, is incredible. A kid down the front’s waving a glow stick; Okereke tells him to keep it handy, and then lasers. The song sounds huge, what feels like a million voices singing the words right back at the figures on stage. It might not be an indicator of the band’s direction for album three, but Ally Pally, for four minutes or whatever, is united in awe. Another highlight is a wonderfully tender – surprisingly so give this massive venue – take on ‘So Here We Are’, a personal favourite from the band’s debut long-player.

Everything’s over in a flash; the bus rolls past previously rented lodgings and suddenly memories are muddled with modernity. The Bloc Party of 2007 is an astounding force to be reckoned with, and an arena-filling one at that. Basements the nation over might be missing out, but it’s for the benefit of you, me, and thousands like us.