I'd say it went pretty well
First I got out, grabbed my bike and started to walk (the store is like 15 minutes away from my place when walking. Mostly brought the bike so that I wouldn't have to carry the bags later.)
Nothing really happened on the way there, but once I got to the store I asked someone who worked there (Might be it was the manager, but I'm not sure since I couldn't read his name-tag) if it was ok for me to do my shopping while wearing the mask and he was all "Yeah, it's just nice with a kitty around". As I was shopping he came up to me and asked me some questions (Like if it's uncomfortable/hot in there and so on) and a little while later I was done. So I paid for my stuff, went out, took my bike and started to walk back home. Then there was this woman with two young children who walked past me who went all "Oh, lookie there.. see? A kitty!" and it really made my day... All three of them looked really happy (I might sound like a suicidal doomsayer most of the time, but I actually love to make people smile.)
Not much else interesting happened on the rest of the way, and as soon as I got back into my apartment I fell to my knees and felt my head spin like crazy.. AIR!!! (While the ventilation in there was great, I have a terrible "sleep-debt" and even tho I'm not exactly fat I'm not too fit) I almost panicked as I tried to find the zipper (I'm slightly claustrophobic), but after a short struggle I finally found it and managed to get the head off... The light stung my eyes and the feeling of fresh air made me feel like I've just woken up from some odd dream.
The last part wasn't too pleasant, but everything else made it worth it. It'll probably be a little while before I dare to do this again, but it sure wasn't the last time. Next time I hope to be able to get some pictures taken and maybe have someone around who can help me with the zipper in case of an emergency... (They say that you shouldn't suit alone and I now see why. Even tho I was only wearing a head I almost got in trouble, so I can only imagine what it'd be like to be stuck in a fullsuit... x-x)