In the 80's I wanted to be a compiler engineer. Got a masters degree in it and published a paper on LR parsing with original research in the Journal of ACM. The opportunities back then were scarce. Over nearly 15 years I found a couple of gigs that consumed a few years. But it was hard and time consuming to develop the knowledge and skills. I used to study the PCC and GCC source code! I worked on GUIs between these gigs and when Java/Swing dropped, I switched full-time to GUIs. There were far more opportunities and I enjoyed developing GUIs for a time so it was a good switch.