It takes years when you have been born into this whacky culture, but is doable.
From the eatocracy.cnn.com
The Democrats would jump in to portray the Republicans as whacky and extremist.
From the guardian.co.uk
It's a shame when anyone catches religion, especially a whacky American religion.
From the guardian.co.uk
This has been a whacky season nationally, just like last year and the year before.
From the dispatch.com
This is mainstream science, and the idea isn't a whacky as you might first suppose.
From the infowars.com
My grandfather always wore one of those whacky musical ties on Christmas Day.
From the smh.com.au
The concept of life surviving inside comets for example, is also whacky IMO.
From the guardian.co.uk
So many letters relayed ingenious solutions without getting too whacky.
From the denverpost.com
There's no reason to suspect the last several weeks will be less whacky.
From the dispatch.com
More examples
Cockamamie: ludicrous, foolish; "gave me a cockamamie reason for not going"; "wore a goofy hat"; "a silly idea"; "some wacky plan for selling more books"
Balmy: informal or slang terms for mentally irregular; "it used to drive my husband balmy"
Whacky was a strip in the British comic Cor!! and ran in the comic from its first issue on 6 June 1970 until 29 September 1973 - some 9 months before it was merged with Buster. It started as a half page strip but proved popular and was given a full page several weeks later.