Sacha,
Well, no formal training for me on bass but I did study piano as a kid and then clarinet through high school. Mom taught piano, dad played upright jazz and in the Minnesota Orchestra, older brother played flute, organ, guitar and bass - so I couldn't escape if I'd tried! A lot of what I learned on clarinet, including reading rhythms, intervals, and hearing melodies, kind of transferred over to the bass and explains why I solo as I do - slightly odd for a bass player. Probably your background on trumpet does the same for you. It's all related, any instrument you play has an effect on the next one you play.
Carry on.
Jimmy J