"Bhavishya ke bare mein na hum janate hain aur na aap janate hain (Neither I nor you know about the future)," Kumar told the assembly while intervening on Leader of Opposition Abdul Bari Siddique's quip about all being not well among NDA partners.
Kumar did not comment on the reported strained ties between the JD(U) and the BJP over his stand opposing Gujarat Chief Minister Narendra Modi's candidature as the BJP's prime ministerial candidature.
"I had never thought about parting ways, but it happened and I moved forward in life," he said.
The senior JD(U) leader also sought to brush aside rumours that he had played second fiddle to the RJD strongman during their decade-long association and said that he had got the latter enthroned as chief minister.
"Unlike the fact that I had helped Prasad become the chief minister, I never looked back in political life and became union minister and the chief minister on my own in alliance with the BJP and not because of any help from the RJD leader," he added.