Recently, a rationalist heard over social media that an acquaintance - a friend-of-a-friend - had found their lost pet. They said it was better than winning a lottery. The rationalist responded that unless they'd spent thousands of dollars searching, or posted a large reward, then they're saying something they don't really mean. Then, feeling like a party-pooper and a downer, he deleted his comment.

The "rationalist" is wrong on many levels. The value of a goal is not directly correlated to the amount of resources that you spent to succeed. It's defined by the utility that you get from achiving the goal.

There a fairly broad research that people massively over spend for the goal of winning the lottery. On the one hand lottery tickets cost too much for the odds of winning. On the other hand those people who win the lottery aren't gaining as much happiness as you would commonly expect. People aren't comfortable with handling large amounts of money if you just hand it to them.

According to self reports pets are a good way to deal with depression. There are also report from people that they are in strong emotional distress because a pet goes missing.

People are truly irrational when they spend too much money on lottery tickets. They are not irrational when they spend a reasonable amount of resources on searching their lost pet and then feel good about finding it again and expressing that feeling.

To know whether someone is rational you have to look at the value calculations behind their actions and not on the values they talk about for signaling purposes and to feel good.