TL;DR I have decent experience in playing a number of instruments and am wondering if I can take grade 5 theory without having taken any theory exam before.
Basically I've been on and off about music for a long time now (played piano and some Chinese instruments, plays bass now for school orchestra) but I never learnt theory properly. I think I have decent knowledge, just can't put a name and structure to things.
I want to take music more seriously now, and plus I don't have any ABRSM practical grades either, so I really need a grade 5 theory to get me going. (I can take grade 7 or 8 double bass easily, but theory is hindering me) I don't have a teacher, but am willing to commit. Is it possible for me to learn all the way til grade 5 myself, and how long would it take?