With the forklift you will stay at 45k forever and probably make less every year whereas for the teacher this is a starting salary and will go up. Talk to real blue collar workers and from most you will hear a not very rosy picture. Pay stagnates, management treats them like crap, terrible working conditions, very hard on the body so getting older is difficult.
Unless you are a business owner or in a very good union blue collar jobs aren't much fun.