I think a monento is some sort of Italian ice cream treat.
A memento from getting a pilot's license is... the pilot's license itself.
I have a drawerful of wings from when I was a kid and pilots on commercial flights let kids into the cockpit then gave you wings to pin on. By the time I was in high school and flying myself, I had enough charts, E6B computers, pencils, and other assorted flying stuff that I needed to tote around that the last thing I wanted was some other thing I had to deal with.
I will note that in my personal view, actually pinning wings onto myself would have been highly-effective girl repellent and I was not interested in that. My wife, who was herself flying at the same time, has confirmed this. YMMV.
If wings make you happy, get some.