I think it's for two reasons:
1) I don't hold back. A lot of people don't like to show affection [in that form], so they give a weak-ass hug that shows very little. I'll put on the Bear Hug Of Death™ in any and all situations. I commit myself to the action. ;)
2) I think I need a hug too. 'Tis better to give than receive, but really with a hug you can't help but receive at the same time you give!
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Now offering free hugs to any and all requestors, though you have to find me to collect.