It was just always going to be. I didn't have any other ambition half as strong as flying aeroplanes, but I thought it wasn't for 'ordinary' folk like me.
In my late 20s I met a few people through work who flew, and realised 'if they can do it, I should have no problem'. Started with gliding but got fed up of being launch point fodder (clocked up a lot of tractor hours and not much in the air) so went to LAC at Barton and within 7 months, in summer 1979, I had a PPL and a Chipmunk share. 32 years later I still had that share having flown many other types in between (basic Cub and a Yak 52, in which I also had a share for a few years, came close to my beloved Chippy for pure flying fun, but the Yak was too thirsty).
On a different angle I also knew of one CFi who outside the flying club held a very mundane lowly job. Once within the club he changed wore a different hat and was suddenly someone to be respected and admired and frankly a bit of a Hitler and an Ego hence the question what motivated you into flying?
This is something I came across in gliding instructors. Some of them were just awful... not competent or confident and because of that they were 'little Hitlers' in the air. I haven't come across it so much in power flying, but heritage railways have more than their share of loco crew who think steam loco driving is rocket science (it's actually very simple but does require 'awareness') and try to maintain a false mystique over newcomers qualifying for the footplate.
Invariably the ones displaying that attitude never amounted to much in real life, outside the heritage railway. Those that have come to the footplate form successful outside careers rarely show such attitudes. They don't feel they have anything to prove.