Flop No. 1?
During the first week of classes at the University of Connecticut (where I was to get my first M.A. in Judaic studies), there was a big welcome cook-out over at Hillel, so I decided to go outside my typical box of comfortability in order to schmooze with the campus Jews. At that point, it was August 2008 and I had been an "official" Reform Jew for about a year and a half. I'd slowly been taking on more kashrut, especially after Passover 2008 when I decided that I was set for an Orthodox conversion. I didn't kasher anything, but I kept on my tradition of no pork and no shellfish (which I'd taken on even before I went to a Reform shul for the first time many, many years before) and decided I was going to avoid mixing meat and milk.
While waiting in line at the cook-out to grab my own kosher burger, salads, and chips, I spotted little packets of ketchup, mustard, and ... GASP ... mayo! I started to get really nervous, looking around to see if anyone else was reacting to the mayo on the table. I mean, they said this was kosher meat and that all the fixins were kosher too, didn't they? Okay, okay, so I wasn't fully kosher, but I wasn't about to mix meat and dairy! Come on people!
Yes. I thought, stupidly, for no apparent reason, that mayo was dairy. Yipes. The thing is, I never really ate mayo, so my ignorance should have been expected. Luckily, I didn't make an arse of myself by saying anything to anyone and instead Googled it the moment I got home. Can you imagine how stupid I felt?
Flop No. 2?
Living in the dorms, I canceled my meal plan after one semester because I simply didn't like going to the cafeteria and the kosher cafeteria (the reason I bought the plan to begin with) was on the other side of campus and I just wasn't into the schlep (my dorm was right next to the building in which I worked, the classes in which I took, and the library in which I lived). Thus, I had to rely on the groceries I picked up every week when Tuvia (who I started dating at the start of my time at UConn) came out and picked me up and drove me over to the Wal-Mart. I got into a habit of eating vegetarian in my dorm almost exclusively, but at some point I was craving meat so I ended up eating a lot of breaded chicken patties, and I made sure -- really made sure -- to never mix meat and dairy, despite my own frustations with chicken as "meat." (I think I thought I was a Karaite.)

(Note: I haven't found a good replacement for Chicken Parm, unfortunately with the gluten-free thing. Eggplant Parm just isn't the same. Oh Morningstar why must you have wheat?!)
Flippity Flop!
The thing about kashrut is that it's a journey, and it's one that isn't at all easy or always fun to travel on. I stopped eating pork and shellfish probably sometime back in 2003, long before I even knew there was a Reform shul in town. But I started there because I knew there was something I could start with that was easy to do and it would connect me to generations of religious and assimilated Jews.
But after that, it took me until 2008 to really even consider the idea of separation of meat and milk completely, and even after I started, Tuvia and I still ate out dairy. But after I went to and returned from Middlebury, Vermont, in Summer 2009, I couldn't do the eating-out-dairy thing anymore -- I felt like I was cheating, being hypocritical. Not everyone feels that way, and I don't expect anyone to feel that way, but we did. And then? We went on that big journey of kashrut together. And now look at us -- we're all super frum with the kashrut.
And it's still hard. I don't know if it ever gets easy. Every now and again I have cravings, strange cravings, for things like Chick-Fil-A and Chipotle and other places that, to be completely honest, I wouldn't be able to eat at anyway because I'm now gluten-free. Saving grace? Maybe HaShem is trying to give me an easy time? Probably not. Cravings are cravings -- they don't go away. But the nice thing is that with modern cooking, you can pretty much figure out a way to satisfy any craving with creative cooking. Likewise, leaving in Teaneck has us pretty spoiled foodwise.
Don't worry about making mistakes. I grab the wrong utensil more often than I should, and we end up doing a lot of kashering (sorry Tuvia!). One of the wisest things I ever read (or was it heard?) was that as long as you acknowledge that there's a goal (in this case being shomer kashrut), then your mistakes and stumbles will not stand in judgment of you. Or something like that. Basically? As long as you say "I will, someday, be a kosher Jew," then your steps and missteps to get there will be accepted as growing pains rather than your downfall. Stick to your guns, and you can make it happen!