Thinking in terms of rate can still be used to wrongly justify things to yourself. Or can be used by others to make things seem like a good deal. E.g. I should

Thinking in terms of rate can still be used to wrongly justify things to yourself. Or can be used by others to make things seem like a good deal. E.g. I should start a new hobby because I am definitely going to keep at if for 5 years! And then you don't.