sometimes we 'think' if we cut this thread 40" long and double it up we wont have to re-thread so often...and your right, you don't have to rethread so often, you just get to spend all your time untangling tangles. It really is much faster to cut 18" of thread, sew along till it 's gone then rethread. much nicer...
and i have been very guilty of this so i do know, it took me forever to finally give in and start cutting my thread much shorter, knot the cut end and
if you really don't want to stop and rethread...do what i do, i thread about 10 of them at once, line them up on the pin cushion...as i run out of thread on one i can just grab the next one...and if i run out totally it's is definitly time for a break anyway :)