i sent you something borys, and we have been steam friends for a while
here is the thing - if you signed up for steam with some weird email address that you never check, or you never sign in to the service, you will never know when you receive gifted games. if you do not set your spam filter to accept email from steam, your gift emails go into the spam folder. games only show up when you click the pop-up when you're online, or you click the link in the email. they are not automatically added to your games list, and you are never shown as owning them.
i've still got games i gifted months ago sitting in my "manage gift/guest passes" window showing as "sent" but not "redeemed" by the people i sent them to
so,
1. Use a real email when you sign up to Steam
2. Set your spam filters to accept anything from Steam
3. Always click "open my gift" on the pop-up, or the link in the email, even if you aren't going to install right away, otherwise it does not get added to your games list
Huh, I just checked, and it is showing you as already having PB Winterbottom, even though when I sent it Steam said you didn't own it.