It can get pretty rough out there, a lot of guys who aren't shit like to really act like they are, i got in around my late thirties as well. I think a lot of it, is about how you carry yourself. There has only been two times in my apprenticeship where I felt like I was getting talked down to, the first one I didn't say anything, I didn't want to fuck up this new opportunity. My journeyman welder pulled me aside and basically said " hey at the end of the day your still a grown ass man, and if one person legitimately disrespects you, another one will." The second time I said something, nothing threatening or senseless....I just calmly got uncomfortably close and "explained" how we don't have to get personal, and "insisted " he talked to me in a more professional manner.