At least Francesco Bagnaia, Maverick Vinales and Fabio Quartararo became hilarious with the joke “Pinjam Dulu Seratus” (= lend me 100 first).

Don’t know why it sounds funny and becomes hits among local people. There is no point on it but everybody laugh when hearing such a joke which can be inserted in any conversation with any topic.
Yes, we are used with such funny lines since a long time ago that we don’t even know who firstly initiate those lines. It became popular without explanation.
For instance :
Kamu tanya? = Are you asking?
Bodo amat = what a heck
Tapi bohong = but it’s a lie (“but what I have told you is a lie”)
Bercanda bercanda = kidding kidding
Aku ra popo (Javanese) = I’m okay (even though I had a bad luck, for example)
Mana tahan = How can I bear it?
All of the lines are expressed in cheerful moments only, during chat or conversation.
Say, somebody asks you a little help, you can say “pinjam dulu seratus”~

