For me its hard to pin point a single thing because till now I don't have done something very big but I always try to reduce my fears step by step, fear of society, fear of speaking, etc.
It keeps on increasing/changing means when I was a child I used to think that this specific task is amazing and only brave people can do it but as I grow the definition of "brave" keeps on changing for me and I'm damn sure that in future my present definition will also get changed but with these thoughts I don't stop myself in doing the tasks.