pull a Knievel
To unexpectedly keep a promise, such as to show up for a date/appointment, attend a boring business meeting, pay a debt, or otherwise honor a spoken agreement which the speaker did not anticipate being fulfilled. Is a nod to the famous motorcycle daredevil who prided himself on always keeping his word, no matter what the difficulties or risks.
My buddy had asked me last night if I wanted to go fishing today, but it had dawned kinda damp and blustery, so I’d figured I could just sleep in. Little did I know --- that dude decided to pull a Knievel on me and showed up after all!