You are not an old man...
I went to technical school for electronics right out of high school and have worked at Medtronic Inc for the past 16 years. I worked my way from a production worker to a high level engineering position, but I eventually hit a ceiling and knew I needed to get back in school.
Since my degree was from a technical school I had to start over (which was painful) in an AS business, then eventually a BS in Management and am currently back to get my MBA.
I am 35 now and I have to say it was one of the better decisions I have ever made, it was difficult starting from the bottom at my age, but it was the right decision. When I am done I will have 17 years of experience with the leader in the implantable medical device industry and a master's degree.
I say go for it and don't look back!