I would think that if you need to return repeatedly to your questions, even long after the project has ended and you're not sure of the dates of it, that you're doing something wrong. Best to trust the site to have good searching.
What I mean is, while the project is underway, and you're nervously checking to see if anyone has answered your question about a specific syntax error or what some function is for, an ordinary bookmark or the links from your profile page will work great. A year later, when you run into trouble and say to yourself "I think I asked about that on StackOverflow", the best thing to do is come to the site and search. You might find your old question and its helpful answers, you might find someone else's question (maybe along the way you might find a more recent question you can actually answer yourself), but you're sure to find a solution to the problem you're facing. And that's more important than a link to the question you asked before.