Olsson admits West Brom almost gifted Man Utd easy three points
Olsson admitted his side rode their luck on Saturday, but the defender believes memories of those past performances provided an inner strength which allowed West Brom to mount their fightback.
"We weren't as solid as we have been and they had enough chances to put the game away," he said.
"But when you play against some of the best players in the world you expect that kind of thing.
"The thing is, when you have been down a few times, you have it in the back of your head that if you fall behind again you can come back.
"We just felt if we got a goal, United would start to get a bit nervous. We took advantage of it.
"After that, we could have taken more, although a draw at Old Trafford is still a very good result."
At least Olsson was able to clear up the confusion over the first West Brom goal, which he ensured crossed the line after Edwin van der Sar had clawed it out.
"I would like to claim it but it was Patrice Evra's goal," he said. "He got the touch that took it behind the line. I put it in again just to be sure but it was already in."