There are a lot of great players out there who can play the crap out of a fast tune and make it sound really good. They play with rhythmic perfection, alluring ornamentation, and notes that are beautifully in tune.
The rest of us however, need to slow it down a little and learn how to really play the tune before we fire it off at lightning speed.
In my tune-learning experience, I find that in almost every tune, there is always that one little part that is either a challenge to bow, or there is an odd string-crossing, or the melody just doesn’t go naturally where you think it’s going to.
For some reason it’s our tendency to play these harder parts faster. Maybe we speed them up because we just want to get them over with. Kind of like pulling off that band-aid quickly so you don’t feel the pain for as long.