Like age 8?
As a kid I really liked flash games and animations and wanted to get into it. I couldn't do flash, it looked too complicated but I found a little software by the name od KoolMoves that was just a simpler flash animation tool.

I did a bunch of shitty stick figure animations in it (hello to everyone from stick figure death theatre) but eventually I realized that I can make it do things (interactive menus, choose your story kinda things, move the player around, shoot...!)

I fell in love with AS1 and later AS2.0 and made bunch of demos and proof of concepts for systems and games. Most are lost to time and datarot by now)

Age 12
Eventually I found out I can make the entire Windows machine do what I want using first Batch files and later Visual Basic script (made a skype bot!) At this point I was also really into graphics and logo/web design

Age 15 - 20 or so
Then it was pretty natural to move to actual Visual Basic, then C# and finally I to C++. And I had the C family in my heart forever. I managed to get a but into 3D graphics too and got a part-time in archviz

Even by this point I never believed I could be a programmer as a profession. I thought of it just as something I love, but have no chance getting into compared to some of the names out there. I half expected to be either doing graphics (cause I found it simple at the time) or some shitty random job in an office.

20+
Finally I decided to go to uni and study software development, see if I can touch the future I always dreamed of! And... Well... I found out more than 80% of the people there never touch a language up until now and most people are just as retarded as I thought..

For a while I also worked as a game designer (still not being comfortable calling myself a programmer, so I chose a non programming position) but I ended up going into the code and improving and fixing game designer tools (it was unity and C#)

After seeing actual programmers at work in a company, and talking to a bunch of them I realized I already have everything I need to do this seriously and with that experience out of the way I breezed through uni, learned to love Linux and landed a proper job :)

I kinda hope my experience with long lasting self doubt will be useful for someone

A little story of death
root@user:~# rm -rf /