How do I get over my laziness? I keep wasting a lot of time sitting around doing nothing and regret it afterward.
Asking for a strategy to overcome laziness means you believe it's possible to beat it. And you're right. Any negative character trait can be beaten. But first, it helps to understand where laziness comes from.
In Shaar HaKedusha, Rabbi Chaim Vital explains that we all have two souls. One is the divine image within us, the seat of our creativity, intellect, and sensitivity to holiness. The second one is an organic, metabolic soul—sometimes called the animal soul—that powers our bodily functions and drives. This is where we need to focus.
Like everything in our world, Rabbi Vital explains, this animal soul comprises four primary natures: the nature of fire, of wind, of water, and of earth. Each animal soul carries a unique composition of these elements – and so the unique character traits each person grapples with in life.
Laziness is earthy. After all, dirt is heavier than fire, air, and water. It drifts to the bottom of things and gets kicked around beneath our feet. Like depression (also earthy stuff), laziness is characterized by a sense of heaviness and lowliness. That's one of the reasons laziness is so hazardous, because it's right next door to depression and can slip you in there very easily.
Yet as heavy or overwhelming as laziness might get, it still remains a manageable trait. It's just soul dirt, after all, and like any dirt, you can get up and shake it off any time you want.
In chapter 41 of his classic work, the Tanya, Rabbi Schneur Zalman of Liadi offers a guided contemplation for laziness-busting:
First think of how G‑d is truly great, a masterful king over all the worlds He created. He is found within all things and yet is beyond them all, so that for Him, all is the same, all is equal. Now think of how He nevertheless brushes that all aside to focus on us little people down here on this speck-of-dust planet and on you in particular. Yes, you, because the Mishnah says that every person is not only permitted, but must say, "For my sake, the world was created." Meaning that this entire universe is waiting for you to get your act together and fix it up—because that's what it was created for.
In other words, G‑d put you here for a particular mission that only you can do and upon which everything depends. Who has time to be lazy?
So important is the contemplation, that the Rebbe advised people to learn it by heart so they could easily review it on a regular basis. Especially at those times when the couch is tugging you extra hard.