Is muscle memory really a thing? My PR from November or December is 215 lbs for bench, but over the winter I slacked off and only hit the gym once every 2 weeks on average, and now I think I could only bench around 195 lbs. How long should it take to recover?

Also 2 days ago I did 3 sets of 8 reps of 135 bench, and yesterday I biked for 20 miles, but my chest hurts more, even though biking 20 miles is certainly much more work. Why is that?