They misunderstand what the change would be (y'know, happy)

I love most of your comment but I don't like the common concept of antidepressants as "happy pills". It's the same issue as depression means you're sad. Depression is a complex illness with a large variety of potential symptoms. In severe depression people are more likely to describe themselves as numb or emotionless than sad because they've become emotionally exhausted. Sadness also isn't the only negative emotion linked to depression. People with depression experience higher levels of guilt, shame, agitation, and anger.

For my subjective experience, I couldn't tell a difference when I started taking SSRIs. They were making a difference because family members told me that I was easier to be around. That I didn't snap at them or brood as much. I didn't realize that I had been snapping at them. Bupropion on the other hand made a big difference to how I felt almost immediately. It eased the physical symptoms of depression, gave me more energy, and made the agitation of dealing with people build slower. Neither made me happy, they made me less depressed.

Feeling better about myself and being happier with my life took much longer and involved therapy and life changes. That's why I don't like "happy pills" concept. Antidepressants are just one piece of the puzzle. They're a tool but recovering from and/or managing depression requires a toolbox.