Just recently stumbled upon this puzzle so still might not understand something. Regularly I find myself in the situation when I cannot deduct concrete number anywhere on the field and, as a result, I just guess some number and continue to solve the puzzle looking if everything is ok or I move to dead-end. If dead-end then I return to the position before guessing and make another guessing.
It isn’t fun.
Am I doing something wrong or guessing is indeed a part of the puzzle solving?
Try to throw the puzzle into sudoku.coach’s solver and you’ll find a ton of techniques that completely eliminate the guesswork.
I find sukdokus extremely fun and I never need to guess on a 6/7 out of 10 in difficulty. My suggestion is to take it slow at lower difficulties to get acquainted with the simpler techniques before springing to the harder difficulties.