It's not a show I readily liked, actually. I got into it after a while, but that's not important.
What's really depressing isn't realizing something's been recent and then gone within a short period of time, but rather when you stop to think about the exact amount of time that passed since. Like, when watching Modern Family and seeing the baby that had to get recast now like an 8 year old, and you're like "How the heck long has this been on?" The adults look exactly the same, but kids grow up fast. You can say that about any sitcom or TV show featuring kids, actually. It seems like the kids jump years of their lives in a season (and sometimes it's because of shooting vs airing schedules), but then you realize that a year of a kid's life is full of growing, and adults pretty much look the same and take longer to change. The end result is jarring.