In English the meaning of my name can be found on Page 1125 of The Really, Really Big Book of Baby Names. In Mother it means I'm about to be lassoed into some novel unpleasantness. It's an off-the-shelf generic name. If I ever change it, it will be to something new and different. This reminds me: I helped English teachers in Polish classrooms and every class had six kids named Przemek.
I didn't start truncating it to "Will" myself but the kids in school took it upon themselves to do so and eventually I went along with it. I self-identify either way, depending on my mood and the formality of the situation.
The best moment for "William" was when my childhood sweetheart said "Oh William" to me in the summer of Grade 8 after I said something that would have to study for three more years to achieve the status of corny joke.
The best moment for "Will" was near the end of Grade 11 when my classmates shouted it repeatedly during my candidate's speech for the position of Student's Council Vice President. They shouted and stomped and cheered.
And like how this is going, my friend running for President ran out of time and they cut his mic.