Instead of trying to kill him and mess up the timeline he instead sits down to have a drink with Hitler.
The time traveler looked at Hitler and asked “So how are you doing?”
“Pretty terrible, I just got kicked out of art school.”
“Well that sucks, you’ll probably land on your feet though.”
“Yea you’re right, but you want to know what I hate?”
“Let me guess, Jews?”
“Well, now that you mention it…”
Another funny joke posted by The_Grout, originally seen on Reddit.