I find this happens to me when I am out with friends, occasionally I will do an approach, particularly if I want to explain / demonstrate PU to them, and it never seems to go well, I think partly because it is approval-seeking behaviour "hey look at me, I'm so great, I can get girls"... and partly because it's difficult to commit to an interaction if you're not fenuinely ready / willing to ditch your companions and go off on an insta-date or whatever -- you're keeping track of them, minding their emotions etc and it distracts from being in the moment. That's not to say you can't approach -- sure, give it a whirl -- but be prepared for disappointments and unsatisfying interactions that could've been great had you been free / in a better headspace.
You could check out Richard / Zphix's posts, apparently his mum wings for him at times, hahaha.
Ray