Even if you sport a rather lengthy mane (which I'm assuming you do) once every six months seems way too infrequent.
Six months isn't enough time to grow a lengthy mane! As I recall, it took much longer than that for me to grow my ponytail, and various internet sources confirm that hair grows at about six inches per year. (I haven't had a haircut since late 2006, but my hair seems to have maxed out in length some time ago.)
I wasn't saying that it would become lengthy in 6 months, but that any haircut which can be maintained for 6 months without a trim has to be a lengthy one. My understanding is that, to maintain healthy hair, it is recommended you get a trim once a month (for split ends and what not.) I keep my hair fairly short (clippers on the side, "finger" length on top) and get a trim once every few weeks (I taught myself how to cut my own hair to make this more convient and affordable. Also, my sister is a cosmetologist so she can fix any mistakes I make ...
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