Bad mom

Are the preschool years supposed to make me feel like a bad mom?!?! Moments of the day I feel like my son doesn't listen and my patience wears thin... I love him so much and don't abuse, neglect, or anything of the sort... But it's like I'm enjoying parenting less. Then there are sweet moments in the day or especially at night when he's sleeping, that I totally feel like he's growing too fast and I need to cherish my time with him better. Anyone feeling like this?