He used a lot of the same riffs over and over again just putting a slightly different twist on them.
For instance, some choir directors use a vocal exercise that goes “Me My Me My Mo”. Mozart uses similar notes in both Figaro and Abduction from the Seraglio.
And NB that K448 has phrases which begin with the same two notes which he uses in Eine Kleine Nacthmusik.
That said, Old Ben can’t play any instrument, can’t read music, and hasn’t been in a choir for half a century. So I do defer to actual FR musical experts.
Yes I noticed that a lot in Mozart pieces, he will play a riff, a sequence and then play the same riff ascending or descending. Still though, it’s unbelievable how he wrote all this stuff out and while poverty stricken. I actually went to Salzburg back in 1995 and saw his birthplace. They had actual manuscripts written by him on display and what astounded me was there were tourists from all over the world there.
What’s funny is I realize today thanks to technology the ability for a musician to make a living is ironically back to where it was in the 1700s. The record industry is dead, so they either have to go on tour and perform or give lessons or be contracted to make music.