The Seesaw Effect of Strength Gains

It's really hard to make consistent strength gains over the course of time. As an overall generalization over the course of a year you will make strength gains, but in the span of a month's time your strength gains will always go up and then down.

The reasons for this are many. You lack motivation. You're sore. You take too long a rest between workouts.  You don't eat enough. You don't eat enough before a workout so you don't have the energy to complete your workout. I could go on and on.

The point is to keep focused on your gains in the course of a year rather than in a month.  Don't beat yourself up if you don't make a gain in the short term. It's human nature to lose motivation or skip workouts. You'll lose strength if you miss a workout but keep in mind  how you progress over the course of a year.