Your quads are probably feeling stronger than ever, and rightly so; you work them all day, every day, without even realizing it. But not every leg exercise is meant to target the quads. The hamstrings, calves, and glutes are just as important to a well-rounded physique and functional strength. Make sure you understand which muscle you should be targeting with each movement, then concentrate on making that muscle do the work.
It's OK if you want to take a moment to stand in front of the mirror today, admiring your tree trunks. Just remember that the people standing behind you are looking at your hamstrings, calves, and glutes, so don't neglect them!