Wackadoodle

Within an hour, forty people were stuffed into his apartment, all carrying gifts, dressed for a party, and it quickly became obvious he'd prearranged a party for himself and not told me. Okay. That's a bit wackadoodle.

Source: wiktionary

You will discover this soon, if you haven't already: Exposure to pregnancy and moms with newborns often causes otherwise rational people to say and do inexplicably inane things (and don't even get us started on the people who started out not-so-rational; they turn completely wackadoodle).

Source: wiktionary

I thought that was totally wackadoodle. How could they possibly love someone they've never met?

Source: wiktionary

"It's not funny, Mom! I use that mitt all the time. What kind of wackadoodle poops in her sister's baseball glove, for crying out loud?"

Source: wiktionary