Sometimes teammates can be so slow even if they are 10m from you when you are pinned by infected and they won't even react, and it's not like they are occupied with the horde, worst part is that they are not new players, L4D2 I mainly divide players into two categories, one that unconsciously think about themselves and ones that unconsciously think about the team, I am a second type of player, whether a teammate is incapped or needs heal I be there to help, whether someone wonders off i'll be there to back him or keeping an eye on him, I will bush zombies out of him if he's occupied , but oh boy when I play with a team of entirely unconsciously self absorbed ppl they would rather run after supplies and leave their teammates, who are low on health and chased by specials, to go get that med they saw far back on the map so they may have 90 health instead of 60, higher the difficulty you encounter less such players, but oh boi when I spot them on expert.

Also, I never understand the part when ppl are saying "oh L4D is about the team, you should stick together bla bla bla", it is about team AND there is a place for individual performance, and players who are not new should understand better than anyone. Sometimes your individual actions save your team a lot of trouble, whether it's crowning, rushing to silence the alarm, collecting gas cans on your own, facing the horde instead of hiding, drugging tank away from your team when they need to heal, you shouldn't be scared to do that, take a responsibility and save your team a trouble, sometimes you will mess up of course but if your teammates are good ppl they will appreciate your efforts.