I have been playing SC2 since 2010 and got up to masters, while switching from not playing at all to being very active all the time. My history with Broodwar was basically playing campaign since I'm a a little kid, then starting with SC2 and coming back, knowing about esports and stuff, start a random 1v1 in the old Battlenet and gettin' beaten up hard, to not play broodwar for another 5 years or so.
Since the ASL launched and especially since the release of Remastered I have been watching Starcraft a lot. After all these years I got a little bored by SC2 and for some reason I am more excited about Broodwar than ever. It this game with a huge history, all these different popular players, maps and strategies. Looking at that from my perspective, I feel pretty hyped and there are so many little nuances to the game, that it kept being interested.
My motivation to start learning Broodwar is twofold: I discovered this awesome series from Day9, which has a very reasonable starting point and gives me some sort of direction. Also I experienced, that I played a few 2v2, BGH and ladder games. Of course I got still beat up, but I actually won some games. Due to my mechanics from SC2, watching ASL and playing the campaign through multiple times, I still suck, but I observed that there are even worse players actively playing. It is really motivating, that even now there is a realistic chance to win.
It is funny to play Broodwar with my prior knowledge, because while I play, I know how bad I am actually performing. I see these overminerals, the fact that I should expand, my production facilities are not in sync, I don't build workers, but I can't do ANYTHING. It is somewhat a pain, because I know I can do better in SC2, but here stuff just won't move as I want. At the same time I have a lot of fun. I sometimes imagined how I would relearn SC2, so this is kinda it, learning a new starcraft, which is similar in a lot of ways, yet very different. This feeling when I snipe lurkers with my marines, or when I use my camera to pump out mech units from my factories, then pick them up from the rally point, it feels very different from SC2, but it feels really good, because I need to work for it.
I want to give a shout out for the great content on Liquipedia. It has been much more helpful than the SC2 strategy part, since patches do not outdate the builds and stuff. Still, I feel when I try out a build order from there, it doesn't feel right, I feel like I am doing a lot of things a few seconds too late and I tend to have to many unspent resources. Next thing on my ToDo list is to analyze a replay from Flash and pay very close attention to the many little non-obvious things going on, like worker production, building placement and rally points.