When I was first starting to get passionate about learning new things and wanting to do more than just the A4 expectations, TED was my go-to source for inspiration (that lovely 2010-2014 era when it was really amazing!). At that time, doing a TED talk on the need for and benefits of space exploration was my biggest dream of all :)
Perhaps I should still give that a go.
RE: How to get yourself on stage on a TEDx event