What you say sounds a lot like looking for excuses. It doesn't matter if there are reasons for why it may not be you. The thing that matters is that you should

What you say sounds a lot like looking for excuses. It doesn't matter if there are reasons for why it may not be you. The thing that matters is that you should always try to improve yourself and if you have two consecutive, independent experiences with the same outcome, then it's a good hint that you can start to work on yourself there (instead of improving your coding skills or updating your vimrc file, for instance).