Taking it easy the first semester/ year may be an excellent strategy especially for some premeds who simply must produce a competitive app in all respects (GPAs, ECs, etc.) It may be better for some to tap on brakes at the beginning, maybe even slow down and wait to apply towards end of senior year (as opposed to after junior year), if that’s what it takes get it right the first time you apply.
Students will often try to create tight schedules for different reasons (eg work schedules, ECs, athletics, maintaining FT status for FA in order to graduate on time, etc). So instead of taking a class at 10am and waiting around to 4pm for some “interesting class” (who determines interesting anyway?), they may take an arguably less interesting, perhaps an easier class at 11am to free up day for whatever else they have going on.