Two senses live under lěi: 'pile up over time' (积累, 累计, 日积月累) and 'pile trouble onto someone' (拖累, 连累). Both come from the same image - stacking things up - but the second sense narrows to the burden you transfer to others.
mistakes
Don't read 积累 as jīlèi. The tired-累 (lèi) is a feeling; the accumulate-累 (lěi) is an action. Same character, different verb, different tone.
Top 5 strokes - graphically 田 (field), but historically a stack of silk cocoons. The accumulate sense fits the original picture cleanly: heaping bundles one on top of another.
