Having spent most of my childhood on a bike
I carried this into adulthood, but cycled mainly for transport, with only the odd leisure ride (in jeans and t-shirt etc). Had bike nicked just before leaving uni, and bought a fab Raleigh tourer; moved abroad for a couple of years, and the bike was forgotten about, and I believe eventually given away (pity, it was a great bike, and I could have made more of it). Didn't cycle then for 6 years or so, and eventually bought a bog-standard MTB, which again, I used for transport and the odd venture out into the countryside (I was in my 30s by this time, had 3 kids, and leisure time was limited).
Following redundancy, I got a new job in Newcastle, moved to Northumberland, saw the countryside, and just HAD to get a bike. Bought a £30 second hand MTB from a colleague (I still have it, it still gets used), then graduated to a roadie (nowt special, but I've had in for 9 years, and it's changed my life!!!!) Now have a tourer too, and basically plan my life around cycling!