Your previous standard should occasionally become embarrassing.

Looking back at old work and wincing means your judgement has outgrown your former output, which is what improvement feels like from the inside. Work that still looks fine to you years later is not necessarily good. It may just mean your standard has not moved.

Go back to something you made a while ago and see what you notice. Discomfort is a good sign. If everything looks acceptable, ask where your standard has been sitting since then.