I'm currently delightedly watching the development of a former colleague who is developing her cycling ability ahead of a Maggie's Ride/Walk in May.
She started training in February - quote from Facebook:
"Second day on a bike......a woman at least 10 years older than me over took me jogging uphill! It is seriously the most horrendous exercise ever! I don't see how I'm going to be able to cycle 20 odd miles by May!" and she commented that this was about a mile's cycle.
Over the intervening weeks I've seen her post details about gradually increasing lengths of rides; she's now up to about 25 miles.
5 March: "Can't believe I'm actually going to say this but I'm starting to really love being out on the bike! That 7 minutes spent with [] hurtling down the bridges changed my whole perception of cycling!"
12 March: "12 miles cycled today. Have to admit there were moments that were horrible but I made sure that Arthur's seat played his part in training me today"
6 April: "Can't believe I'm customising my bike! Who would of thought :)"
and finally 11 April: "Best cycle yet! Up the bridges peak traffic, pouring with rain, thunder and lightning, speckles of dirt hiding the fact I need to shave my legs. Brilliant, so much better than cycling in the warm weather :)"
I love that she's gone from hating it and doing it as a horrendous chore for charity, to loving it :)
I can't say that I've had any personal involvement with getting her cycling (although I did post encouragement at the beginning) - but it reassures me that adults can take up a bike and enjoy it just like kids.