pessimistic
Always expecting things to turn out badly.
Pessimistic means expecting bad outcomes or focusing on what could go wrong. A pessimistic person looks at a situation and tends to imagine the worst possibilities. If dark clouds appear, they assume it will definitely rain and ruin the picnic. If they're waiting for test results, they convince themselves they failed.
This word is the opposite of optimistic, which means expecting good things to happen. While an optimistic student might think “I studied hard, so I'll probably do well,” a pessimistic student thinks “I'll probably fail anyway.”
Being pessimistic isn't the same as being realistic or careful. A realistic person considers both good and bad possibilities and prepares accordingly. A pessimistic person can get stuck expecting the worst, which can become a self-fulfilling prophecy: if you're convinced you'll fail at something, you might not try your best, making failure more likely.
Some pessimistic thinking comes from past disappointments or genuine challenges. But persistent pessimism can hold you back from opportunities and make life feel heavier than it needs to be. The pessimist sees the glass as half empty, while the optimist sees it as half full. Both are looking at the same glass, but their expectations about what comes next are completely different.