We mourn with you the passing of your youth, colleague: you have paid the price of an active life, and of insisting upon walking on your hind legs. Now is the time to pass along accumulated wisdom to younger fellows, known in some settings as mentoring; in others, as hazing.

Pain related to spinal issues is tough, but you have borne it well. Beware the transition to numbness in the affected part: I failed to do so, and have areas on my left arm and leg that have no sensation, no proprioception, and considerable muscle wasting.

We wish you well.