Christopher Jullien doesn’t even flinch when asked about his favourite Celtic goal.That Betfred Cup Final winner against Rangers at Hampden was memorable for a whole host of reasons.It was a game the Hoops were dominated in - but still came out on top.It was against their Old Firm rivals.And it was the big French defender’s first trophy success since arriving last summer for £7 million.But what made his strike even more special was that he got to celebrate it with Celtic fans in that south east corner of the stadium.The knee slide, the fist pump, punters spilling on to the track.That will live long in the memory for Jullien, as well as for every Parkhead supporter.And that’s why the centre-back shudders at the thought of having to play