You’ll usually see this quotation weaponized after a breakup: “Respect yourself. If you don’t, others won’t either.”
I say that you’ll see it “weaponized” because in those cases what’s really being said is “I didn’t get what I wanted, and I’m upset about it.” The intent is less to build up the person saying it, and more to tear down a (specific) person hearing it.
You can also see it in the way it was originally meant – that women are typically socialized to defer to men, and that deference doesn’t lead to politeness or respect. Deference there leads to becoming a doormat.
But it can also mean that you should respect what you’re able to give. Maybe your time is limited, or you can’t move, or, or, or. If you don’t respect what you can (and can’t) give in a relationship, you won’t be respected either. It’s challenging when you really want a relationship to happen, but if you don’t respect your own abilities – and what you’re able to give sustainably – then someone’s going to feel disrespected real soon.
And I think it can also mean respecting what you’re willing to receive – that is, what “price of admission” you’re willing to pay. The other person has (or wants) children and you don’t? They’re poly and you’re not? They don’t want to marry and you’ll only be happy if you do? You have to respect your own boundaries and be honest and open about them. Otherwise, the other person(s) in the relationship will seem like they’re not respecting what you want… even though they’re respecting the boundaries you said out loud.