There is an interesting trivia of this song. The first line of the song's mukhra is taken from the theme songs from The love theme of romeo juliet. The song is also known as " A time for us" which was released on 1969. If you take the notations of the song and reverse the notation you will get the tune of " O hansini" by rd burman which was also told to be inspired from the theme song of "summer of 42" by michael legrand. so either its a co incidence or the summer of 42's tune was based on reversing the tune of a time for us. Rd burman took the opening bars from summer of 42. and either bappi straightly lifted from a time for us or took the rd's song and reversing the notation of the first line he made "Mana ho tum".
Interesting. But I guess, if one goes by one line similarities, then there will hardly be any song in the world that can be called an original. Given that we have over crores of songs made so far, and just a handful of notes to make them, one- line similarities can very well be incidental or coincidental often.