It is a good and useful habit.
This is from pattern for the current Z Top project. Notice how I have circled the stitch count for this exact point in the making of the thing.
And, I hit that number spot on the first time. The stitches were zipping along, the color was pooling, and everything was perfect.
Pride goeth before. . . . and all that.
Cast your eyes down toward the bottom where the pattern has changed from crochet to the knit portion. Those numbers are stitch counts. Do you see any circles or markings of any type?
My brain went on the fritz and my fingers merrily started binding off and knitting and binding off and knitting based on a casual glance. And when I made it all the way round those starting 168 stitches there were oh, maybe a gazillion stitches left over!
Do as I say, not as I did. Mark your pattern people. Mark it all the way from cast on to wearing.