I also thought like that but it seems we were wrong about Leverkusen and they continued to progress without ever tasting victory. But at the moment there are still a few matches left and if we talk about the next match against Stuttgart, I think Leverkusen can still overcome this. The reason is that in the first meeting at the start of the season, Leverkusen did have difficulty facing Stuttgart but they were able to stage a comeback win in the 90th minute and that was enough proof of how their mentality works.
Leverkusen always refused to lose, there were many matches they scored a goal near minutes 90 or injury time.
Yeah the upcoming match against Stuttgart will be interesting to watch, this season both Leverkusen and Stuttgart have improved a lot among other teams in Bundesliga. I think it will end in draw, but I won't really surprised if Leverkusen lose in this match.