You're defending it because you've already spent five years on it
When the past becomes an excuse to sacrifice your future too.

“I've already spent five years on this.”
So you've decided to spend a sixth. Excellent plan. If the first five were a mistake, you urgently need to make it more convincing.
You say this about a job you hate, a relationship that's been empty for years, a project kept alive by transfers from your savings account. Asked why you should continue, you tell the story of how much you've already invested.
I asked about tomorrow. You're showing me yesterday's receipts again.
It's convenient to cast the past as a creditor. There it sits, demanding: give me back my youth, my money, my sleepless nights. Prove it wasn't all for nothing.
And you pay. Another year, another loan, another attempt to revive something you're keeping alive purely out of respect for your own stubbornness.
But the previous years won't come back if you stay. They're already spent. The question is how many more you'll put beside them to avoid saying something unpleasant.
Sometimes continuing really does make sense. Difficult stages exist. Long timelines exist. Some work takes time to produce visible results. Not every disappointment means you should abandon everything.
Then explain what will change. Why will the next attempt be different? What have you learned? Which conditions are new? What result will let you distinguish patience from repeating the same shit?
If the only new argument is “now I've invested even more,” the situation hasn't improved. Leaving has just become psychologically more expensive.
Try taking your biography out of the conversation. Imagine being offered this exact job, this exact relationship, this exact project today. On the current terms. With the current people. Knowing everything you know now.
If not, it helps to identify what's keeping you there. Obligations? Money? People who depend on you? Those are real issues that need a plan. Or are you staying because you need to look like someone who got everything right five years ago?
You can bury a lot of your actual life trying to protect that appearance.
Then there are the spectators. You told everyone what a wonderful choice it was. Defended it over dinner, argued with friends, explained why they didn't understand. Now leaving feels like publicly admitting they were right.
Maybe someone really will say, “I told you so.” They'll experience this extraordinary high point of their life and go eat dinner.
You'll still be living with the consequences of your decision. Personally, I wouldn't trade several more years just to deny some asshole fifteen pleasant seconds.
Leaving costs money and effort too. Sometimes you first need to settle obligations, find income, reach an agreement, prepare a handover. You can leave gradually. Keep what works and drop what's been dragging you down.
You don't have to spectacularly burn everything to prove you're free now. But it helps to stop calling the wait for a miracle that vindicates your old choice a plan.
Five years can leave you with skills, connections, experience, and an unpleasant understanding of your own limits. That's already something. You don't need to pay for a sixth year just to give the previous five a nicer name.