I used to seek out tough challenges that had tight deadlines. Early in my career. This helped me gain a lot of knowledge about my craft. However, now that I've acquired a lot of knowledge I don't go actively seeking work I'm not being asked to do. It's not because I don't care, but it's because I value my life outside of work.
The other part of this is that there were never tangible rewards, such as a raise or promotion (besides the experience I acquired) so at this stage in my career by asking to do extra work and spend more stressful hours in a salaried job environment for nothing in return would ultimately be a bad decision on my part.